The breadth of testing scenarios was impressive: The cards were tested on both Intel and AMD platforms, at a variety of MTU sizes, and a variety of interfaces, from 32-bit/33MHz PCI to 64-bit/66MHz PCI. From all this testing, several interesting trends can be seen.
First, gigabit Ethernet cards laugh at your puny 32-bit/33MHz PCI bus. Cards that peaked at under 200Mbps on a 32-bit/33MHz bus turned around and peaked at over 600Mbps when put on a 64-bit, 33MHz bus.
Second, speed costs. While some of the cheaper cards could churn out a respectable 600Mbps or so, that was typically only at certain MTU sizes; in tests with other MTU sizes, they'd drop to half that. The only card to consistently post high scores across nearly all MTU sizes (and the only card to really take advantage of 64-bit/66MHz PCI over 64-bit/33MHz PCI) costs $570. A $138 3Com card makes a respectable second-place showing, but for whatever reason, it performs substantially better on a slower 64-bit/33MHz bus than on a 64-bit/66MHz bus.
I'm just rambling now; go read the article if you're interested in this kind of stuff. If GigE switch prices come down in the future as much as the cards have recently, it could be the next hot thing for people like us who look for as much overkill as possible in our computing experience.