Damian's right. Blades seem to be so subjective, mainly because they work differently depending which razor you have. Even the 'worst' blades have a few fans, so buy some of both. If you have any left of the ones you don't like you could always PIF them or swap them or even sell them.
as with the others, i would say you have to give them a try. My instinct tells me that the gillette is the higher quality blade. I actually have both of these in my collection, and will try giving a supermax a go tomorrow and see how it stacks up against the gillettes.