I had a pack of Astra SP's I got as a sample with an order. They've been sitting in the medicine cabinet for months now and I finally tried them tonight in my 37C. My go to is usually Feathers or Gillette blacks, but I was blown away with the smoothness and sharpness with the Astras'. I ordered 100 for cheap, it will save me some money in the long run, as I don't get many shaves out of a blade with my beard.