@Rob:
Partly, as they also don't have the standard cooler/heatsink setup (like Phase 5 cards) designed to cool down the rest of the chips on board besides the 603e. On my card, I've also installed mini heatsinks on other chips, just to make sure that they are properly cooled.
Other than that, the card is a rev. 2, which is important if you plan to use Grex1200 with it.