650ti is an inferior card than 7850 alright. but when you consider sheer value the 650ti is currently an exciting proposition.
AC3 free is probably one of the best offer i have seen on a entry to mid range card ever.
i would have bought the 650ti for that great deal alone.
but since you not interested in AC3 the 7850 will be a better long term investment for you and in general for people who dont change their gpu every year
so go for 7850. personally i would recommend sapphire or msi cards.
i dont like the big ugly cooler on gigabyte while it does a great job of being cool.