I think I'd call GEM SS blades the most mild. I get the best results from GEM stainless blades. I have tried the PAL Supers and Treet supers, and while they still provide a nice shave, I just don't like them as much. Plus, the carbon blades require a lot more maintenance or they rust faster then could imagine.
When it comes down to it, I think the razor has a lot more to do with a mild shave than the blades. The blades I have tried don't seem to have nearly the range in sharpness or smoothness as DE blades do. In the end, I'd say pick up one pack of GEMs and one other carbon blade and see if you prefer one to the other.
Andy.. I believe a guy should try to smell his best at all times-Richie Cunningham