Ok so I'm still going through my first sample pack trying to find my blade. I am using a 40 style Gillette SS and I have average to light facial hair. I started off with the Derby, and right away I didn't like the blade, but I gave it a few more chances with no improvement. Then I moved onto the Personnas and the first shave was amazing, I was very impressed with how much hair it cut on the first pass, however I was disappointed with the fact that by the third day the blade was completely dull, I thought maybe it was just a fluke so I loaded up another one and same thing third day dull again...I still like the blade but now I am moving onto crystals, then astras, and finally finishing off my pack with feathers. I will edit my post as I go through the rest of the blades.