Mine doesn't seem to fit very well on the top. Not sure if it's just something to deal with or not. The amazon reviews said the measurements were off initially, but otterbox claimed they had adjusted after release. I also realize like my one for my 4S, the damn flaps on the bottom will be cut off sooner rather than later, annoying!
I just got the phone yesterday, so I'm still figuring it all out. It's definitely weird changing after having the 4S for 3+ years.
I have the otter box wallet which is basically the commuter with a CC holder. It's not quite as good as the old fit at the bottom at first, but over the last 24 hours it seems to have relaxed to fit almost right.
ETA: the screen protector that came with it was a tiny bit small. There is about a fingernail width between the edge of the screen protector and the edge of the rubber at one point.