Or you know you could reinstall iOS via iTunes pretty easily. Why do you need a genius bar?
And by carefully disabling every background process - what exactly do you mean? Other than mail checking - what user controllable background processes are there?
Closing Apps in the multi-tasking switcher has been the only way, on both the iPhone and iPad, to save your battery when apps on iOS run out of control.
I certain I'm not the only person who has felt their iPhone get hot, and shut down everything in the switcher to recover the and stop the battery from draining?
Likewise with the iPad, making sure every music, every voip, every downloading, every geo-fence, every GPS, every-single-app is shut down is the only way I can keep my iPad Battery from draining after running a good handful of apps.
That, or just powering it down - which, as I said earlier, kind of defeats the purpose....
And by carefully disabling every background process - what exactly do you mean? Other than mail checking - what user controllable background processes are there?