I have a Specialized Pro Sirrus hybrid that has Shimano hydraulic disc brakes. They were, in part, one of the reasons I bought the bike 'cause they made the bike look very cool - great reason to buy a bike I know. I really like them on that bike.

My gut reaction is that they are better all out brakers than the Campy Record rim brakes with standard pads which I have on my SAECO Replica 'Dale. They probably do not have as much "feel" but that may be a function of my not being that used to them as that bike does not get much use. Discs would definitely be better where brake fade was an issue.

There are two problems: First they make getting the wheels on and off harder. You have to insert the disc into the pads and sometimes they need to be retracted. Second I'm guessing that the total weight of the disc system, including the small resovoir, is greater. I think they would be a great idea - and they'd look really cool.