Sapphire's HD 7950 Vapor-X is a well-rounded custom design HD 7950. It comes with an overclock out of the box that gives it a 4% performance lead over the reference design HD 7950. Sapphire used AMD's dual BIOS feature to put a second BIOS on the card that runs the card at even higher clocks of 950 MHz, resulting in another 3% improvement. What makes this mode much more appealing is the fact that Sapphire did not increase the GPU voltage to achieve stability. As a result, power, noise, and heat are not significantly higher than in normal mode, which is why I recommend all users activate Boost mode as default. This leaves normal mode without a real benefit. It would have been nice if Sapphire had optimized the normal BIOS for super-low noise-levels, easy given the low temperatures. I also miss an overclock on the memory.
The card's Vapor-Chamber cooler does a great job keeping the card cool and improves noise levels greatly compared to the AMD reference design. I still see some headroom for improvement, which would come in handy against competing low-noise GTX 670 / 660 Ti cards like the ASUS DC II, one of the best choices for low-noise high-end gaming on the market.
Overclocking on our sample worked amazingly well, reaching over a 30% real-life performance improvement. In our testing at maximum clocks, the card ended up faster than GTX 680 or HD 7970 GHz Edition - at a fraction of the price. Of course overclocking varies from sample to sample, so your mileage may vary.
In terms of pricing, Sapphire is asking a not unreasonable $330, which is $30 higher than the currently cheapest HD 7950 card available; the GTX 660 Ti does offer a better price/performance ratio though. Overall, you should definitely consider the Sapphire HD 7950 Vapor-X if you are in the market for a HD 7950.