I have upgraded my work MBP, MBA, and 24″ iMac to 10.7. So far, things have been mostly smooth. Unusually so, given the scale of changes in this release.
Overall, I quite like the changes that I’ve noticed. Full-screen mode is great. It reminds me of the Netbook interface in Ubuntu 10.04. I look forward to better application support.
The biggest improvement from my perspective is Mission Control. The combined Expose and Spaces view is an improvement to window management.
I’m in a bit of a crunch time at the moment and despite the upgrade mid-stream, 10.7 hasn’t gotten in my way. In fact, I’m liking the changes.