I wanted to get an opinion on which card to buy for a new HTPC I built. I don't really game but wanted better than integrated graphics. Radeon 6670 seems to have the best balance of power, price, and efficency. For the price, XFX and Sapphire seem to be the best options with DDR5.
The main difference between the two is the Sapphire card comes with a Displayport. Does that justify the $10 increase in price? Currently I only plan on hooking the HTPC up to a TV. Is the Displayport a feature that I should get for an HTPC perhaps as a future-proof?
How does the HD6770 do for power consumption, noise, and heat? I would consider paying a bit more but I believe the HD6770 would require it's own power which may lead to more heat/noise. I do not really require a powerful graphics engine for games but processing power for HD video and audio is paramount. I believe I read that you cannot do better than the 6670 in terms of HD video processing. The higher end Radeons use the same core as the 6670 for video processing.
While the Radeon HD 5670 cannot handle mosquito noise reduction without dropped frames, the new 6570 and 6670 can. This means that the pinnacle of AMD's video image quality (a score of 201, according to the HQV 2.0 benchmark) starts at the ~$80 Radeon HD 6570, and more expensive Radeons offer nothing better. This is a significant improvement over the GeForce lineup, where the top-scoring cards achieve about 160 points.
Your suggestion for paying a bit more for the displayport is noted. I am leaning towards the Sapphire card - they're a good brand.