Before you decide, wait for the Apple announcement this coming September. If you ask me, I'll go for the Android phones. You have a wide range of selections, for every budget and size. I'm a Note 2 user, and I don't think I'll go back to smaller screens. That's me though. It depends upon your targeted use. Apart from basic phone calls and texts, I use mine for email, social media like google+, web browsing, media consumption (movies and music), news (flipboard) and some games.
And for my usage, bigger screen with good dpi is nice. Plus most of the apps that I want are available on Android. I'm excited with the rumored note 3 with octa-core, 1080p screen and 3GB RAM. I'm a spec whore, he he he. But there are also rumors about a budget friendly iphone and a bigger screen iphone. It will always boil down to personal preferences and needs. If the your must use app is ios-only, then you have bo other choice but go for an iphone.