I decided to post my experience with the GM after I saw another thread citing a bad experience with iOS5 and the 3GS. I can say without a doubt that iOS5 runs better than 4.2.1, 4.3.X. I kept my phone on 4.1 due to choppy animations, slowdowns, etc on those software versions. iOS5 runs perfect on the 3GS. It's very smooth, the animations are smoother than 4.0. The notification center pulls down perfectly. The folders open the smoothest I have ever seen. In general, it runs perfect. Maybe people who have had trouble just got a bad install or something. I've had nothing but good experiences with iOS5. As usual, make sure to close down apps once in awhile since the 3GS has memory constraints. All in all, I'd say if you are a 3GS user, you should definitely upgrade.