I got one Derby blade with my Muhle R89. Tried it hated it. I also have an unopened 5-pack of Derby's from a sampler that I will probably never use and they should go to someone who will love them (or at least someone who's never tried them). Just say you're in and random.org will pick the winner next Sunday the 10th.
I could have sworn somebody around here said they liked them. Oh well, if nobody takes them I'll just mail them to someone randomly.