Pick Up the iPhone 7 or Wait Until Next Year

Havent owned an iPhone since the 4, but I'm due for a new phone this fall and I'm strongly considering returning to iPhone and picking up the 7. That said, I've heard rumors that the 7 will offer minimal changes, while the 2017 model will bring big changes. If I make the switch back to iOS, should I just get the 7, or get a 6s with what I assume will be a price drop and upgrade again next year?