Mike G.

No, the only way to roll back is to restore a backup made before the upgrade.

I know you posted in Feedback, but some creative suggestions for the creative community managers out there:
- You can reduce the # of posts that appear per page in a topic.  Really! Most admins rarely change this number (and why is 25 posts the magic number anyways??) but if you insist on symmetry, reduce the # of posts to match your sidebar length.  
- Add relevant blocks for users that help with self-promotion or content discovery. In other words, utilize all of that emoty sidebar space! Add your guest sign in widget, newsletter sign up widget, Community Hive widget, popular content widget, our picks widget, recent comments widget, etc. to inspire and grab your user deeper into your ecosystem.  
- If the Topic Summary is the only item of your sidebar, think about switching to the Compact View that layers the Topic Summary into the posts.  That will eliminate the sidebar completely and give you clean aesthetics.  

I think personally I would dispute the idea of 'dead space' as a concept. You don't have to fill every pixel of a page with content, and doing so could actually have a negative effect by taking focus away from the actual content people are trying to find.
Facebook doesn't do it, Reddit doesn't do it, Instagram doesn't do it, so that should be a good indicator I think.

This is remarkable. 
Will there be a way to adjust the length of the snippets? I like the idea, but I wouldn't want them to be too long. Trying to strike a balance between enough content visible to get people interested in the conversation, but not too much so that they still have to open the topic to read more. 
I was going to watch a Netflix movie but I think I'll watch that video 6 times in a row instead. 😍
@Ehren for the win!! 

It's truly amazing to see how easy the theme editor is. The amount of possibilities are really endless. And that will definitely be fun to see various communities making their own version. Having a 3rd party theme designer create something like this custom for you is worth alone thousands of dollars. This version takes your community to a whole new level. I don't think people can really comprehend how much work goes into this.
Brilliant work team, well done. Couldn't be more excited to see more!

It's also worth noting that the removal of JS and CSS removes render blocking items, whereas cover photos are additional bandwidth but do not stop the page from rendering until loaded.

I am honestly blown away by how good all of this looks. I honestly wasn't expecting such a massive leap forward in design with v5, so this is all quite a wonderful surprise to me.
@Ehren and you all have done an amazing job with all of this.
Modern desktop resolutions have gotten so large now that we have such a massive amount of wasted real estate on the sides, even with widgets and everything else filling up some of that space. Migrating to a sidebar layout to capitalize on this just makes a ton of sense, and also makes navigating around seamless.
The new mobile layout looks wonderful too, along with the new forum layouts and everything else. It has been a long time since I've been this genuinely excited about a new IPS release.

AdminCP theme settings 🤔
Where we're going, we don't need no ACP theme settings.
Next week's blog should really help clear up what theming looks like in v5.

Spoiler: It'll be very different.

That quote is going straight into the top of our marketing.
Also, may I recommend:

Honestly, though during the initial building phases back in early summer we used to have a weekly sync meeting with Ehren as he's in Australia and everyone else is not and he'd take us through concepts, and ideas and we'd all just say 'wow' for about 20 minutes.
Now I just send him badly annotated screenshots and broken HTML I mangled at 2am his time while he's sleeping.

Are you hiring?

Welcome to the second video of our sneak peak series! Today we'll be taking a closer look at the new Invision Community interface, including dark mode, accessibility improvements, performance improvements and the mobile layout! Before we begin, I should mention that this is a pre-alpha version of Invision Community 5, so some areas of the design may change before the official release.
 
New traditional header design
In our previous video, we showcased our new, optional side panel which formats your navigation into a vertical list. For those who prefer a traditional, horizontal header, here it is!

A much more compact header compared to version 4, the new design condenses the navigation bar into a single row, moving all sub-navigation items into dropdown menus. A new, optional area below the text logo allows you to add your website slogan or announce events such as anniversaries or holidays, and our new search modal provides convenient access to the advanced search filters from any page on your community.

 
Accessible interface
The main content area has been designed with accessibility as a priority. High contrast text colours and larger font-sizes help to make reading more comfortable and clickable table rows (which can be enabled or disabled via the Theme Editor) allow you to navigate between pages more easily. A visible focus ring significantly improves navigation for visitors who find it more comfortable to browse with their keyboard TAB key, instead of using their mouse (ie. visitors with conditions such as Parkinson's disease, or those who have temporarily lost function due to a broken arm).
 
Focus.mp4
Elements are highlighted while navigating with the keyboard
 
Dark mode
Dark mode has become increasingly popular over the past few years - so it's no surprise that Version 5 has been designed from scratch with both light and dark mode in mind. With version 4, it was necessary to manage two themes in order to provide a light and dark colour scheme. In version 5 though, all of that is handled by a single theme.
By default, your members will be able to choose their own color scheme preference: either light, dark, or system. System assigns a color scheme based on your system preferences - so if your device automatically switches to dark mode at night, your community will too! With that said, as an administrator, you also have the option to restrict your site to a single color scheme - so if you ONLY want to offer a dark theme, that's easily achieved.

 
 
Performance
Despite all of these new inclusions, the version 5 UI has been coded with significant reductions in both CSS and Javascript. We'll dive deeper into code reductions in a future blog entry, however two great examples are:
- Grids: which have had a 100% removal of Javascript and are powered by only a few lines of CSS, resulting in a faster rendering time, especially for users on slow connections.
- And carousels: which have had a 95% reduction in Javascript and now rely on native browser scrolling, for a much smoother experience on both desktop and mobile!
Additionally we've removed a number of helper libraries that are no longer needed with modern browsers saving even more.
 
Mobile UI
With an incredible amount of mobile visitors accessing the web, we’ve placed a huge priority on redesigning the interface to ensure it lives up to todays standards.
A new navigation bar at the bottom of the page provides convenient access to your activity feed, notifications, messages, a search panel, and navigation links. A conscious effort was made to ensure that this information was available within a single tap, and we found that a bottom bar like this was easier to interact with compared to icons in the header.

The mobile navigation bar from Invision Community 5
 
A goal of the mobile UI was to display elements that were previously only available on larger devices, while still maintaining a clean interface. For example, to improve navigation, we've added a scrollable breadcrumb list to the top and bottom of the page. To improve guest participation, we added Sign In and Sign Up links to the bottom navigation bar. These links were previously hidden within the hamburger menu, so we feel like this will really benefit those looking to improve registrations. And as demonstrated in last weeks video, profile information is now available within posts, comments and reviews on small devices.
We’re really excited for you to literally have a hands on experience with the new mobile interface of Invision Community 5, and we're interested to hear your feedback in the comments!

View full blog entry

Talking more to myself: 
So, the Sidebar Menu gives more space.  And more space means more opportunity to share links. And more opportunity to share links means we can customize the menu experience for different journeys of users: the new you, the returning you, the future you.
For the new you, I can see the first 3 menu links be things like "best of", "top guides," or "must read" types of links.  Essentially, items to help a new user get oriented.
For the returning you, I can see the first 3 menu links be things like "what's new", "my content" and trending content.  Essentially, items to help the returning user catch up and jump back into the latest conversations. 
It's hard to do that kind of personalization with the horizontal style, but I can see the Sidebar Menu empower community admins to create "personalized" menus in a way that most admins haven't done (or thought about!) before.  This is some food for thought that I think all IPS admins should consider as a takeaway when we re-envision our communities on 5.  
This is all assuming IPS keeps group permissions on menu items as is.  

It's a better user experience, easier navigation, quicker to access content, requires less scrolling, has a much-improved mobile experience, showcases helpful replies, and so on.
From my point of view, it's very SEO-friendly.

In addition, I do want to point out that we have removed a significant amount of JS that is no longer needed including some libraries that acted as shims for older browsers. The entire CSS framework has been rewritten and is more compact, so there are significant savings already.

This looks absolutely amazing! 

This looks absolutely amazing! 

This is remarkable. I love the new content scrolling feature on mobile. I'm this

close on dropping XenForo and migrating to Invision Community. 😅
Brilliant work to everyone involved. I love the new sidebar. Very cool to be able to link additional threads, forums or other features that are popular. Also, I didn't know Ehren was part of the IC Team. 😄 Good asset !

An update on extensions
 

We've released some news on Invision Community Five, but third party developers won't have enough information to get started on updating their apps. We're at the peak of the mountain now and ready to start showing more in the coming weeks.
I am really excited to start showing off the culmination of just under six month's work from our team.

Never gonna give him up!
At the bottom near the footer currently. There is an 'auto' mode to take the value from your OS.

It's a useful metric for those monitoring performance of the community but agree that I never look at it and decide to open a topic or not based on that info.

I actually agree. I'm not sure everyone would though. But I think a lot of metrics we have scattered around just add clutter and do not add value in determining whether the topic should be read or not.

My goal is to provide a listing directory to make it easy for developers to list their apps.
A directory will provide visibility, scale, and ease for everyone to visit.  
Developers will handle payments and support on their own.  

I know absolutely nothing about development, but this has been a fun follow. Thanks for the continuous transparency and updates as things are being finalized.