Don't put too much trust into people using unofficially released software, especially when the MAJORITY of apps are still going through the review process. Most games need updated SDKs due to audio updates and other stuff. When apps are using deprecated APIs, of course it's going to give you nasty glitches. It's a GM release, yes, but by the time the new iPhones get to people's hands, we're already going to see an 7.0.1 and 7.0.2 update.
http://forums.macrumors.com/showthread.php?t=1637226
You will have over a month to go back to iOS 6. When new .0 updates come out, Apple usually leaves a pretty big gap before they stop signing builds. Use a tool called TinyUmbrella to save the SHSH signatures before moving to iOS 7 if you feel paranoid about it.
I haven't noticed any lag, but my status bar did vanish.