Yeah Ive got a 6950 2gb version too, had it for 2 and a half yrs now and cant see me upgrading from it anytime soon, as it still runs all my games fine.
6950 is a beast of a card, nothing really matches its price range. Was about £200 2 years ago and cards at same ish price today are only slightly better.
Recently 200 quid gave you almost double performance potential (Overclocked/latest drivers) with a 7950.
7970/R9 280X's are around 230ish.