Should I get the 5c or the 5s?

Although I'm a pretty heavy iPhone user, I don't really use apps that require heavy processing power. I'm pretty drawn to the 5S's fingerprint scanner and A7 chip, but I'm not sure if it's necessary to spend $100 more for it. What's your opinion?

Added (1). Also, I have the 4S and I'm looking for an upgrade.

Buy the 5s. The C is basically a regular 5.