Is it worth Upgrading a HD 5770 to a XFX 6950 HD

Good afternoon all.. I was wondering if it was worth upgrading my GPU to a 6950 from a 5770.. For xmas I got this monitor http://www.bestbuy.com/site/Samsung+-+23%22+Widescreen+... which will make my resolution 1920 x 1080.. my current monitor is 1680 x 1050..... I have an i7 -870 processor with a Antec 650 PSU.... The games I play are Aion, Steam games.. L4D, L4D2, Bad company 2 and will play GW2 when it comes out......... The total cost of the 6950 including tax and all will $317 for the XFX card sice it has the warranty.( i have never had an XFX card)