It sounds very promising. I will certainly look into it. But my biggest concern about the 5s is that upcoming operating systems will make it slow - especially after the release of the 7. Do you know if there is any truth in that? And how long would a 5s last in composition to the SE?
Thank you for answering!
I would go with an SE if you don't mind the size. It is more powerful, newer, has better battery life than both the 5s and 6, and it also has a better camera. And 2GB of RAM which was a sore spot for me on the 5s and 6 (they had 1GB)
The 5s and 6 are pretty comparable devices in terms of power (the A8 in the 6 is more or less a slightly enhanced A7), whereas the SE is both cheaper and more powerful than the 6 (the A9 made some big gains in CPU power and especially GPU power); it also has more RAM and faster RAM.
If size is your main sticking point, then perhaps give the 6 a test run at your local electronics store and see how that goes, because it does have (imo) a better screen than the 5s or SE.
But the SE is the best overall, I think. It is buttery, buttery smooth on iOS 9 and will last for a while; the A9 chip is a mobile beast.