The Activity Streams are a great way to organize and keep track of content which is important to a user or group. I personally use them for support on this forum because we are responsible for a few forums and it allows me to view things as they come up.
On my personal community, I use Activity Streams and the Follow system to keep track of everything throughout the community. Additionally, using them together with Activity Stream subscriptions is fantastic to stay alerted. (I like to welcome new users personally when they post in our intro forum is a good example)
Again, this goes back to my own personal community but I have a homepage using the block system to showcase new topics overall, new topics in certain forums (i.e. we have a for sale and traders forum so good to see what's going on), and the Our Picks system to call out important topics. Users have enough information there to see what is going on without needing to see the read status. If they want that, they view the Activity Stream where it tracks that for them.
There are plenty of options and I can move this to the Community Managers' Lounge if you would like to hear from fellow community owners.