My iPhone 4S updated in around 20 minutes over wifi the other day, no problems at all so far.
If anything the battery lasts a little longer now. I got the new youtube app out of the store the same day, everythings running fine, no problems with the lastest version of iTunes either.
Someone up thread mentioned folder-ing the core apps, the iPod touch could do that on 4.3, my iPhone could do it back on 5.0 (iTunes, App, Apple, Remote and iMessage all in one folder).
Just not so amazed by the new map system, and apparently, neither is Apple.