I have had two pair of Avid shorties and both barely made it a season. Avid replaced the first set when all the spring posts came loose. The second pair fit so sloppy on the brake bosses I couldn't get the squeal out of them. I ended up giving them away after a few months of use. However the Avid Ultimate V-Brakes on my tandem has been awesome and trouble free, they should be they cost $100 each wheel. The best cantilever I have ever used is the old shimanos from the mid to late 80's like the BR535 XT or the XT2's which you can buy NOS from
Sheldon Brown I have these now on two of my bikes and they work flawlessly.