Welllll...
This is what I learned about the two.
The iPhone 5c is essentially an iPhone 5, just made with cheaper parts and colored...
The phone itself is basically the same, the only difference is the actually size of the phone... I just got in iPhone 5c cases yesterday to sell on my eBay account and I pulled out one of my iPhone 5/5S cases (those phones are the same size, the 5S just has a duel flash on it) What I noticed is that the iPhone 5c is just a TAD taller then the iPhone 5/5S and much thicker... it also has more of a curve around the corners, so if you do end up getting an iPhone 5c, make sure you get a case specifically for it or it won't fit properly.
It's times like these I kind of miss working for AT&T lol although I hated when they had a monopoly on the Apple phones because everyone would call in and say the same thing, 'As soon as Verizon gets the iPhone, I'm leaving this company!' LOL