After having mine a few days now got to say I am a bit disappointed.
Tonight was at a gig, took a few pictures went to take another one. Camera would crash after the shutter went off. So I reset the phone, same happened again. Also couldn't even look through my photos as that crashed on launch too. Tried a restore still broken can't be used at all. As soon as the shutter animation plays it either just quits back to my home menu. Or I get the spinning logo for a few minutes and then it asks me to enter my pass code. Just resets basically.
With regard to said photo issues, this means any app that requests to see the photos stored on the phone crashes instantly.
I also think the 64GB ones may have a build quality issue. Tried a couple now and they seem to feel like something is loose inside them. Where as the 16gb and 32gb versions seem much more solid. Like my old 32GB 4 was. My 64gb sort of sounds hollow and vibrates when you tap it. Was going to nip it into the Genius bar and get them to check it out. Normally I wouldn't care if it was a minor rattle or something, but this actually feels broken.
Booked at the Genius bar for Tuesday anyway.
After doing some research this is a fairly well known bug causing the crashing. Seems it can be fixed by going into the phones directories and deleting a few files if you have an explorer for the phone. Still in all their testing they didn't notice this bug in iOS5? Can happen on any device running iOS5 if you take a fair few pictures. Taken maybe 200 or so in the last few days.
According to the phone itself I have 2,147,483,647 photos on the device.