Up to today, I had shaved with vertical Derbys, wilkies and Gillette Platinum Chromes. Ok, but not terribly sharp. Today I loaded up an Irridium for the first time, and whoo boy! I had to double check after my first pass to see if I had loaded the blade wrong somehow and I wasn't actually being shaved- it was that smooth. The down side of this for me was, however, that I got a patchy shave because I got so little feedback from the blade that I couldn't tell if It was shaving through anything.