If you're in need of a phone with a bigger screen at this very moment then get one. But if that desire can wait then you wait until the third quarter because I'm pretty sure the next iPhone is coming. I usually do not buy phones generation to the next because I feel that the upgrade ain't that dramatic so I skip a generation. However the iPhone 5s to 6/6+ was really dramatic so I immediately got one once it was released. I think this time an upgrade to 6/6+ is a bit late so if I were you I'd rather wait.