OT: iPhone 6 or 7

[cmbicycles]

I'm thinking about upgrading to an iPhone 6 or 7. I use cricket wireless for service as its cheap, gets reception in my basement office, and I don't use a ton of airtime. I'll be switching from a Samsung galaxy S4.
The iPhone 7 is $100 more (both 6/7 are 32gb), and wondering if those who have had one or both of these phones could comment on plus/minus of either. I liked the idea of being able to use an sd card on the samsung, but haven't even come close to maxing out storage in a few years so not too worried.