HardwareZone checked out Leadtek's GeForce 6600 GT PCI Express. Here's a snippet from their writetup:

Despite the recent spotlight (albeit deserved) on NVIDIA's GeForce 7800 GTX, the graphics subsystem mainstay on many new gaming systems are often those from the previous generation. With the exception of the hardcore enthusiasts who would spare no expense, most consumers would balk at the prices of the latest generation cards. For these users who, when they do play games, do so at more 'reasonable' resolutions of 1024 x 768 for example, a modern mid-range card should be good enough. Therefore, today we take a break from the high-end mumbo jumbo and cast our eyes on the more affordable segment.



Link: HardwareZone