Sharp is sharp. The angle of attack is the same between most razors, which means that they all cut hair. IMHO, however, if a hollow comes up against a stubborn hair, it will tend to flex OVER the hair and save it for another pass. The wedge razors don't care what's in it's way and just slams right through everything. As a result, and I'm sure that it was just because I started out using hollows is that I get less irritation from a hollow as I do a wedge.