I returned mine today as well...except I returned my wifi only model and got a Verizon LTE one.
I love the retina display and LTE is showing speeds that meet or exceed my home wifi. I couldn't be happier. But I can definitely see ur point.
I always upgrade no matter how big or small the upgrade is. I always sell my previous device and wind up getting about 80% of my money back towards the new device. And with subsidized iPhones, I always make more then I originally paid. I haven't paid a single penny for an iPhone since the 3G (I'm in the US so no,I don't pay more in my contract). But if I were to skip a year and wait, the value goes way down. So I'll gladly continue to upgrade every year for a free phone or an $80 iPad.