I have the same problem, and Yea, this is a REAL pain. I have all kinds of work files on my iPad, files I need like NOW, and my iPad is stuck in a loop, constantly restarting.
I have tried the "fix" suggested by Apple (Connected my iPad to iTunes on my Mac, downloaded the software in a process that took well over an hour, and that didn't work. Complete waste of my time.) and that was not only unsuccessful, but it was a dumb "fix" that didn't fix anything.
So, I have a big project that I have made a commitment to have ready by the end of next week. I put all of the documents for that project on my iPad, and now I am screwed. I will be able to fix it myself by "working backwards" to collect all of the documents again, but it is going to take me a lot of time to do something that I had relied upon Apple's iPad to do for me.
I am so glad I did not update my iPhone.
So I am not happy. I'll leave it at that.