I'm doing the opposite. No more S model for me.
3GS > 4S > 5s
Although each phone is an improvement on the last, I always feel slightly underwhelmed. So last year I bought the 5s outright and reduced my monthly contract cost with Vodafone. So when the 6 comes out, if I like it, I will either renew my contract for 18 - 24 months and get the brand new phone with a small upfront cost, or I might just buy it outright, again. Not sure I'm going to stretch beyond £549 though... ouch.
3GS > 4S > 5s
Although each phone is an improvement on the last, I always feel slightly underwhelmed. So last year I bought the 5s outright and reduced my monthly contract cost with Vodafone. So when the 6 comes out, if I like it, I will either renew my contract for 18 - 24 months and get the brand new phone with a small upfront cost, or I might just buy it outright, again. Not sure I'm going to stretch beyond £549 though... ouch.