I'm not trying to start a flame-war if both are quality products and have a following.
We're taking the tandem on a tour from Grand Canyon to Mexico in a few weeks and I feel like I've got one chance to get this right.
I recently put a XT V-brake on the rear of my Trek T2000 to get away from the kludge of a cable stop that Trek installed. The Avid Shorty 6 that came on the bike seem okay, but I couldn't think of a better idea than Trek for a cable stop and final cable routing. Hence my move to v-brakes.
My problem is that I'm not (at all) impressed by the XT brakes I installed. I'm running a travel-agent and they stop the bike quite well, but they don't return to center very well. I have adjusted the tensioning screws and set the brakes up with high and low spring tension. If I remove the XT brake and move it through it's range of motion I find that the motion is tight and jumpy on both sides, not at all ideal so I'm looking for an alternative.
So, has anybody used both (Paul's Motolite and Avid Arch Rivials) or been very happy with a certain set of v-brakes.