I just replaced a
Thermaltake G4-VGA with the NV Silencer 1. Sorry, I don't have pictures, temp measurements, or any of that. I can tell you what you already know - next to the G4-VGA, the Silencer is, well, silent. It's in an Antec SLK3700AMB along with a 120mm exhaust on a Zalman fanmate and a CNPS7000, also on a fanmate. Even with the CPU and exhaust fans turned down about 2/3 of the way, the sound of the Silencer doesn't stand out. I was initially disheartened to hear a nasty clicking noise (not the one normally associated with some speed-controlled fans), but it turns out that now I'm able to hear what sounds like the bottom fan of the stock PSU clipping against something as it rotates.
As for installation, it was no big deal. I did have to remove the ramsink on the front of the card that would have blocked the fan shroud part of the Silencer, but since they are the aftermarket sinks that came with the G4-VGA I'm not concerned too much about heating. The card is never overclocked, and now the temps inside the case should be lower than ever anyway. I was pleased with the mounting hardware - rubber bushings and decent quality screws for attaching via the four mounting holes in the card. No more spring-loaded clips to launch the GPU fan off the card!