Need advice before I finalize this purchase

I'm upgrading from a 9800 GTX+ and I don't need a top of the line card. I have this http://www.newegg.com/Product/Product.aspx?Item=N82E16814127663 in my shopping cart with my mouse hovering over the submit order button but I couldn't do it until I came here. After the promo code the card comes out to $170.

I came across a couple cheap 660s:
http://www.newegg.com/Product/Product.aspx?Item=N82E16814500270
and
http://www.newegg.com/Product/Product.aspx?Item=N82E16814133470

I told myself I wasn't going to spend any more than I've already come to, but would I be MUCH better off with one of these instead?