Those brakes have the potential to work very well. Lose the link wires and go with traditional straddle hangers and crossover cables. Get some Kool-Stop pads too, and clean the rims! Some soapy water and a green scotch-brite pad will work wonders. Just looking at the photos, I'm amazed they even slow you a little! It'd be worth the money to have someone in the know about canti setup to do the work.

Your fork could benefit from some Mag 21 dust wipers, and the quadra 5 was only spec'd for 46mm of travel, and by looking at the clean areas on the upper tubes, it's only getting 25-30mm. That's about normal for those forks.

Your computer wire should be routed along the front brake housing, and down the fork brace to the leg.

Oh, and I almost forgot -- that frame was made in the good 'ol Waterloo factory with more care and precision than 99% of the junk coming out of China these days -- wear it well.