I've been using a 5s for 3 years now, and I don't have much desire to replace it. I don't find it the least bit slow. The only time I get frustrated with it is when network performance is slow or reception is bad, but that happens with any phone.
The 5S was indeed a champ. You might want to hold off on iOS 11, though; I’ve been running a beta on an iPad with the same A7 cpu, and it just can’t keep up.
(Perhaps the 5S wont have it so bad given that it won’t have to deal with the new springboard and multitasking...)
