I don't think it's crashing for me on my iPhone 4 running iOS 6. However I've had issues (not sure if any with GC) on my iPad 2. I'm going to restore it (from backup). I installed iOS 6 by restoring my iPhone 4 (it was jailbroken before).
One thing to note. For some reason iTunes doesn't automatically start syncing your device after the restore from backup finishes. So you have to manually click the Sync button. This worried me as I thought it meant I'd lost all my app data/saves, but I didn't lose anything (all saves and such were intact after the sync).