Lots of issues...
I really had allot of issues with the iOS 6 update today. And so far I still can't use it after 5 hours.
I began my download when they released it earlier this afternoon. When the download completed, the install failed. Apple gave me no reason other than a little message that said "Install Failed". Thanks for the info apple... So I tried it again, and another 40 minutes later got the same message. So I assumed this may be a space issue, and deleted all photo's and videos on my device going from 2.4 GB free to nearly 4 GB free. Even though the update was much smaller than both of these (I know it has to be unpacked after the download finishes).
Third times the charm? Nope. I got it to download for the third time, it said "Processing File" or something like that for nearly another 40 minutes. By this time I am at work. It finally finished with that and gave me the INSTALL button. I pushed that an again what seemed like forever it installed. Being at work I had to leave the phone to itself for a bit, and when I came back, the phone was off. I turned it on and about 1 minute after the apple logo sat there it shows me a picture of a plug with the itunes logo. So I guess I have to wait 4 hours until I can go home and connect the stupid phone to iTunes.
All in all, a VERY POOR update experience. Hopefully no-one else ran into these problems. The thing that annoys me most about it is that my phone is STANDARD, DEFAULT, iPhone 4. It's not jailbroken or had anything done to it. Apple makes the software, the hardware, the distribution network, basically everything, and yet I have all of these issues... EVERY time I go to update a major OS release. Not to mention, when there is an issue, they provide you with ZERO details on the issue.
I'm just really ready to get home and attempt to get my phone back in working condition...