Bugs and whatnot...
Well, I tried the Lion GM for a few days, and overall I really liked it.
Sure, it has a lot of minor bugs still, but as with any OS I'm sure they will be fixed in a relatively short time.
The only major issue I had, was that Lion ran about 10 degrees hotter than Snow Leopard (both on upgrade install and clean install).
The UI was sometimes sluggish, assuming because of all the fancy new animations and whatnot, and the fact that I'm still on a 2008 24' iMac, so I expected some performance hits.
I don't really have a use for Launchpad, personally I don't see the point of it, but that's just me. But I love Mission Control, and the gestures.
There seems to be quite a few nice refinements in Lion, the animations, gestures, etc.
The only thing I think Apple is doing wrong, is rushing this thing out the door. It could stand a lot more tweaking to optimize speed on slower systems. And there are definitely a lot of bugs still. (Although seemingly minor ones, for me anyway).
Overall a great upgrade I think, but personally I hope that GM build is not the final, it's too buggy and sluggish, one more build would be better.