Got my build your own sampler pack and tried the Derby blade after the Rockwell blades that came with my shaver and after the Astra Superior Platinum in my sampler pack. I must say the Derby hacked up my face and left me with a not so close shave and irritated face. They gave much louder audible feedback while shaving and I had to apply some pressure on the blade to get the hair cut. Not a problem so much on the first pass, but very irritating on subsequent across the grain, and really painful on against the grain. So far only the Astra shaves me without nicks and cuts. I'm new to wet shaving and somewhat surprised how different blades can be. I'm using the R3 plate on my Rockwell razor and the Derby blades just don't cut it (pun intended), except for my facial skin.