I own the xfx 4770, I recommend that route. Though I'm also swayed by a good deal. If you have to pay the same, I point to the 4770. I run my at 900/1000(+higher) ~stock is 750/800 and get fps that the 5750(stock) gets. Its a 40nm chip, and has gddr5 mem chips rated to run at 1000mhz, Sooo that explains why the clocks can reach #.
OK, I have been using Nvidia for a little while but my next card may be an ATI now. That sapphire looks and sounds like it runs cool but the reviews are mixed on it which means the quality is mixed. If I run a 50% chance at getting a faulty product or a really good on then I am unsure if Id want it.
I have the older Sapphire 4850 512mb versions and haven't ever had an issue with them. They are my 2nd and 3rd card from sapphire with the first being a 2900xt, which i was happy with.
The only thing that i'm a little sad about is that they arn't the 1gig versions because they had the dual slot for dumping the heat outside the case, but it led the way into liquid cooling for my cpu and cards.