I agree that the search function on IPB is severely lacking. As I was a Dragonfly CMS user for years, which used a version of phpBB, I thought that phpBB's search function was lacking too but I think it was still a bit better than IPB's. I too will use Google to search the forums here and on my own site before I'll use the built in search function here as the results are at times, worthless.
I love the rest of the software and functionality, it's been a very pleasant experience, search just needs some serious help.