So I'm currently running two XFX 4850s in CrossFireX and it runs all games on max beautifully! I've been thinking about upgrading my cards though since the 4800 series is a bit older and was thinking about the 5770s. Reading the specs, they seems similar (same amount of stream processors, etc) except that the 5770s have a higher core clock (850 vs. 625) and run GDDR5 and not GDDR3. Wondering if it's worth the upgrade. I'd be selling the cards of course and using the cash towards the 5770s. Other than DX11 and the available HDMI ports available on the 5770s, are there any other significant gains?