My 5C is still in great condition and I got it back in like 2013 or something. No cracks or huge scratches.

I never bothered to upgrade because

1: I can't, upgrade plans don't even include my phone now so unless I want to drop 500+ dollars for a new phone I can forget about upgrading. RIP

2: I actually like this phone a lot. Its still on iOS 8 but its jailbroken.