I didn't like Derby blades the first time I tried them, but I have since come to love them. I find the quality (of the blade and of the shave) to be above average. And you just can't beat the price.
I love these blades. I use mostly a slim-adjustable. With the Derby it almost seems like no blade at all during the three pass shave. BBS at the end 98% of the time. The other 2% is usually me rushing to get done. I also really like the Wilkinson "Economie", the Gillette 7 O'Clock in the yellow wrapper, and the Astra Superior. Right now I am trying out a Trig that Giovanni had sent me with some other sample blades with my last order. So far two shaves and very nice and smooth. I like it. Next after this will be the PolSilver blade. Steve