So what's the general consensus on these then? As previously stated i am looking at this or the 5850 but seeing as i only game at 1680x1050 i think the latter might be a bit OTT. Has anyone encountered any games where they've had to dial down the settings? I'd like to get one as they're cheaper than a 5850 and actually available but don't want to be left disappointed.
A 5770 would be faster than your 4850, but not considerably so, they are about on par with a 4870 speed wise.
A 5850 would be close to twice the speed of your 4850.