I don't have an iPhone but if I did, I'd rather have 5/5s than 6 because I prefer the former's design. Also Apple will never put one but I wish iPhones have a hard "back" button because I use that a lot.
Samsung should hire Sony and HTC's designers because their (Samsung) phones' build looks so cheap. It's unfortunate they represent a large chunk of Android sales. Even Xiaomi (a rising China brand) has superior design.