new iPhone 7 out in september. Prices will invariably drop on older devices at that point. Regardless if you don't go for the iPhone 7.
I know you stated you were not interested in android, however i just made the move from iPhone 6 to the One Plus 3. Took a bit of using diff apps for diff things but its certainly do able. I think the only thing i miss is the iMessage integration on the iPad / mac etc. Hope this helps.