Still new to DE shaving, I have only tried the following blades: Feather, Astra and Derby.
Clearly the Feather and Astra are sharper than the Derby. I have a pretty thick beard and the Derby seems to struggle a little bit on the first pass.
However, one thing I have noticed is that I can get more shaves with the Derby; and, even though it is slightly duller, it doesn't give me irritation.
Has anyone else noticed that the Derby seems to last longer?