I do not have any benchamark tests, but have been usuing a mkii powerflyer/fastata for years. They are very fast compared to the standard ide port. I have never used idefix, im huessing its not much faster than the inbuilt ide, just gives you more ports.
The main problem with the pwerflyer is that is will use 100% cpu near enough when being used.
Best best is to get hold of a blizzard card that has the scis kit. Nice DMA transfers then. I am still kicking myself for selling mine.
