I actually had one, and tried to live with it. I'm firmly in the camp that you only need one good app, unfortunately often that one app just doesn't exist. It naturally depends on what you want to do but dealbreakers for me were;
- Includes NFC but no payment engine - therefore no Oystercard compatibility on the underground
- Uber - yes available now, wasn't then. I tried to login now but it still doesn't work. Too much hassle both Android and iOS just work
- Waze - same thing just about there but just doesn't have the functionality
- Banking - much more serious than the others, just no app available at all
I was always in the anti camp, but gave in with the iPhone 6 Plus. Then got the Nokia 930, Wileyfox Storm, Samsung Galaxy S7 Edge and now the iPhone 7 Plus - every single one easily fits in my slim fit jeans pocket without any concerns whatsoever. And anyone who knows me knows that there isn't much room left in a slimfit pair of jeans for me

I honestly wouldn't worry about size and pocketability. Unless perhaps you are a skinny jeans wearer