Supposedly the gillette yellow sharp edge is the exact same. A guy on another site examined a bunch of blades with a microscope and they had the same grind and home on the edge and they are both coated the same and made by gillette in the same factory.
I have never tried the iridiums but the yellow are my favorites
I may have tried 10 different brands of blades before trying a Feather, and that was that. Feathers are my favorite, I'm not even bothering with anything else--unless I run out. LOL