First: I have Avid BB7 disc brakes on my full-time commuter bike. I have full Dura-Ace on my Trek road bike and the feel of the brakes is pretty close, but the discs win for all the usual advantages, plus they require less force on the brake levers for the same braking performance. Now if I could just afford electronic Dura-Ace for my drive train. Mmmm.. But I digress.

As a rule, I don't let very many mechanics touch my bikes anymore - and I'm sponsored by my LBS. I like to adjust my brakes especially so I get the right mix between not rubbing and adequate braking power and brake lever play.

I had a similarly bad experience the first time I tried a road-disc bike out. For whatever reason, the brakes on this bike howled like a banshee whenever I slowed. I've heard similar noises coming from mine during a rain storm, but when it's dry or slightly raining, they're normal. I also didn't notice much braking power coming out of the discs I demo'd, so I'm assuming those calipers had oil or something similarly annoying on them. I later demo'd a couple of MTBs with disc brakes - one hydraulic, the other mechanical and said - this is the greatest thing since sliced bread, and bought my current commuter bike. For me it goes along with no such thing as too bright of a headlight.