I've had major problems with IOS 7 on my iPad 3. The download and install went perfectly, and I started using IOS 7 with no problems at all. That was Friday night. Saturday morning it was still fine. I tried to use it Saturday night and the device was totally dead, even though it was left with a 75% charge showing. I plugged it into the AC charger and got the empty battery icon with a red line through it, as well as the lightning icon. After about an hour, the screen came back on showing a 2% battery charge. I called Apple and they suggested resetting the device through the Settings/General menu, but not until the battery level reached 10%. That took over an hour, at which point I reset the device. I tried reconnecting to my wifi network, but it would not do it. At 20%, it finally was able to connect with no problem. All seemed fine, so I left it plugged in and tried it this morning. The battery was at 100% but the device now seemed very unresponsive. I could not change the wallpaper because it didn't respond to the controls. Set for automatic detection of the time zone, it could not find my time zone.
I shut the device down and all seemed to return to normal, with no delay in keyboard strokes. It still wouldn't detect my time zone, and I had to change that to the manual setting to get an accurate time. The other thing that worries me now is the battery level. It seems to be moving way too slow, still showing a 94% level after nearly two hours of use. I'll wait and see what happens here before calling Apple support again.
I'm fine with the new interface and features, although I did disable the passcode feature which was driving me nuts. IOS 7.0, IMHO, is not quite ready for prime time. It has lots of great features, and I'm getting used to the simplified icon scheme, but what a mess of issues. There's already an IOS 7.01 update for the iPhone, so I'm hoping some fixes for the iPad will be available very soon. As of right now, I am very disappointed and sorry I didn't wait for the first bug fixes before I did this irreversible upgrade.