I run a BORB on a Elsa Erazor X2 which is a 32 mb Geforce 256 DDR and lapped it myself, I personally found a noticable reduction in temprature which I believe is due to the moving of the power source. The standard Elsa Erazor hsf draws its power from the graphic card itself and therefore adds to the power consumption required from the AGP slot. The BLORB draws its power from the mobo and when fitted with artic silver after being lapped, my card is fairly cool.
A PCI bay cooler can also help this situation.. hope this helps