I have a newish bike with Hayes MX2 disc brakes. First mechanical discs for me, and overall I'm quite happy with them (woohoo, they work in the rain!) Front brake is fine, the lever is at a good height and the amount of cable travel feels good. No issues there.
Rear brake had a tendency to drag a bit, plus there is a lot of cable travel and lever movement, I'd prefer to engage a bit higher. I was able to resolve my dragging issues on the rear brakes by backing the fixed (inner) pad out until the pad is just peaking out. I do notice that the rear rotor is not flat, so there is a lot of runout. Have tried cold setting / tweaking the rotor with a 12" crescent wrench, but no luck.
should I expect the rotor to be flat? I've no idea how it could have gotten distorted, certainly not from overheating. At what point is a rotor considered defective? Granted, these are low end brakes. Not sure what realistic expectations should be. But if the rotor were flat(er) the pads could be closer together and the brakes more responsive (subjectively, of course).
would the rear brake have a different feel simply because there is more cable to move?