I had no glitches with wifi, but I certainly have noticed a higher level of battery drain. Used to get through the whole working day on my iPad3, now I need to charge up a couple of hours before going home time. I estimate about 15% less working time. I appreciate complaining about reduced battery life after every update has become a "thing" but I'm a heavy user of my iPad, and I assure you, it is quite noticable this time.
Worse though - since I upgraded to 6.01 both my iPhone 5 and (only this morning) my iPad3 have suddenly reset themselves to factory default! I was able to restore both from backup using iCloud, but it's inconvenient, and frankly, a serious reliability worry (not to mention being a pain to do over our overloaded work wifi).
iOS 6.01 seems to be unstable, at least as an upgrade. I'm hoping that being forced into restoring from scratch will also help with whatever causes the battery drain issue.