I use iPhone 5s. For me personally it is important to not to have any problems and clashes with soft and choosing any new phone every year. That's why I chose iPhone. My previous was 4s for almost 5 years, but after unintentional update to iOS 9 it became impossible to use it.

Now 5s fits completely fits me. Hope I'll use it during next 1-2 years.

(If there will not new unintentional updates though  )