Building a bike for a friend and have been given a Clark's CMD 5 disc front brake from another friend for the build. It seems a fine little unit with good adjust-ability…..

Am I wasting my time or are they okay in practice?

Bike is to be used as a commuter with maybe a few towpaths ridden.

Thoughts?

I have only used Avid and Deore cable discs but both were very good. They don't have the power of hydros but certainly better than V brakes and less maintenance.

Good cables (Avid/Shimano/some Tektro … to an extent) can be as powerful as many hydros on the market, but don't have the modulation – although most riders probabbly won't notice to be fair. Cheaper ones tend to need lots of adjustment to keep them bob on and even the expensive ones need a tweak here and there to keep them running sweetly. Hydros tend to be more of a set up once and forget about affair, even if the bleed process is a bit more of a faf than routing a fresh cable.

I would heartily recommend Avid BB7 cable discs for any MTB application except DH and alpine riding (long, sustained use). Their only real disadvantage (as with all Avid breaks I have come across) is that the pads are a little tricky to change.