Summary: This cooling unit took my ATI Radeon HD2600 XT from about 55°C (idling on failing GPU cooler) and 85°C during heavy workload down to 39°C idle and 47°C during heavy work. It's exactly what I needed, and the blue LED on the fan is just a nice added touch (all my other case lighting is blue).
Pros: Does exactly what it's supposed to do, and is pretty to boot!
Cons: Slightly bulky and heavy, was missing one tiny mounting piece.
Summary: I used this Zalman cooler to replace the fan on my XFX GeForce 9800GTX. The stock fan was starting to really let the card get hot, running at about 48c idle and 63c at full load (100% fan running). This card has brought it down to 38c idle and 48c under full load. Excellent build quality, this cooler feels nice and heavy and the blue LED is a nice touch. Installation couldn't be any easier, it's just so simple. Definitely recommended.
Summary: The only issue I could have with this heatsink is that it's not set up to blow air out of the case. Is that an issue for cooling the video card? Not at all. Is that an issue with cooling other components, such as the CPU and north/southbridges? Yes. When your GPU starts getting hot, the air blowing off of it can increase temperatures elsewhere. Is it really such an issue, though? Not at all.
Pros: It's pretty. It's quiet. It cools.
Cons: It doesn't blow the air out the back of the case.