Can only echo the previous statements. Outside of the 3 lines on the horizon the card runs any game, including CLOD, like a dream and the 2GB certainly helps with high texture qualities and resolutions.
Also you can unlock it to a 6970 without worries as it has a dual bios, any of the few cards that end up with artifacts can usually be set back to 6950 stock clocks (or inbetween 6950 and 6970) while still having the benefit of the extra shaders...and if not you just revert to the original bios with the flick of a switch.
http://www.techpowerup.com/articles/...ng/vidcard/159 successful/unsuccessful unlock chart at the bottom
(Not unlocked mine as it's a non-reference design without a BIOS switch)
As for buying a cheaper card and going SLI/crossfire later on..I'm not a fan of it, you need a better PSU, sometimes a more expensive motherboard and by the time you are tempted to plug in that extra card you're usually better off just buying a new single one which performs better than 2 older ones in tandem.
And there is always the odd game you love which hates SLI/xfire.