"Its still only 33mhz though...does it make a difference?"
Not really. Unless you have enough drives to saturate the standard 32bit bus, it won't make any difference. In order to do that, you will need at least 3 current generation drives, and 4 or more of anything older. And even with those numbers of drives, that only comes into play when all the of the drives are running full bore from the outside of the platters. Not a real common occurence.