Was having the Game Center crash upon launching on my iPhone 4 too. So let Ridge Racer log me into Game Center 1st before retrying and it finally worked. The new Maps look cooler but the lack of public transport directions SUCKS! That feature worked so well on the older Maps while the new Maps just gives me a list of other apps to use instead... none of which compare to the older Maps. Hope this improves. Anyway, off to work now.
I've noticed that iOS 6, after running a day or so, hogs about 200-300 mb of system ram( viewed through system monitor) even with all apps closed. iOS 5 never did that. So I'm having to restart every time I want to play Bastion because the game will chug with only 200-300 mb of my ram free (normally I'll have 650mb free upon a reboot/iOS 5 with all apps closed).