I've posted a few times about them here , I love them , the front is like the metz racetec same kind of feel I'd nearly go to say that they're as one but the 01 has a little more steel in it of which you can feel on a more coarse surface with a bit of weight on the front kind of like the bars are directly connected to the axle , I've wilbers front n rear now but had the 01's on before that and coming from metz tourance they transformed the bike , I know the pr4's are good but the 01's really do have that something extra especially if you like front end feel , very hot tyre and quick to heat , to date I've 3600km (EU miles) and the rear still feels round,