Summary: I thought I might be upgrading from the Nvidia 8600GT being the 4670 has twice the graphic ram and about four times the stream processors. But in the end I saw little to no difference in display or frame rates. The 4670 is a good, reliable mid range video card which allows me to game to my hearts content at high settings, but it is still "a last Gen" card that requires 512Mb GDDR3 to compete with Nvidia's 8600GT @ 256MB GDDR3.
Summary: As others have written this is a good value for the money. There's some debate as to whether all of the 1GB can actually be used in a card of this class but you can get more info on Tomshardware and other places online. One of the advantages of this card is that it doesn't require additional power so you'll probably be ok with your existing power supply. What I really want to say in this review is that the fan is fairly noisy.