Conclusion: HR-03 PLUS
The HR-03 PLUS is a fantastic cooler for the GeForce 8800. The only real problem we had with the HR-03 PLUS was the lack of stickiness of the memory heat sinks, and that can be easily fixed with a little thermal adhesive. We also wish it came with a 90 mm fan, as its passive performance was a little too hot for our tastes, although it's certainly close to the stock cooler's performance.
When all is said and done, however, you can't argue with success; the HR-03 PLUS is probably the best air cooler you can put on a GeForce 8800 right now. That alone makes it a good buy if you're a GeForce 8800 owner looking for a better cooler.
The Thermalright V2 is a great cooler and does a fine job lowering GPU temperature compared to a stock cooler.
Our chief concern is that most (if not all) of its competitors come with active cooling fans. While the V2 is expected to have a similar price compared to the competition, it does not come with a fan, and that definitely hurts it from a value standpoint. Unlike the HR-03 PLUS, the V2 has to deal with competing solutions that offer similar performance. To further complicate matters, the V2's fanless performance wasn't quite good enough for us to recommend it as a passive cooler for our 7900 GS test card, although it might work well passively for cooler GPUs, as the 8500/8600 GTs.
However, the V2 has its strengths. If you have a lower-end GPU you would like to silence with a passive cooler, the V2 would be a fine choice. Also, if you have some good-and-quiet 80 mm fans lying around, the V2 might be just what you need.
I'm looking forward to testing the performance of the Zalman and Arctic Cooling GeForce 8800 air coolers against the HR-03 PLUS when I can get my hands on some samples. Then we'll see if Thermalright can keep the GeForce 8800 cooling throne.