I installed Shimano BR550 cantilevers a few days ago and there's a night and day difference between these and the mini Vs. When I rode with my regular shoes I never hit the rear brake with my heels. On a longer ride with SPDs I managed to get heel strike a few times but it wasn't a big deal and I guess it's because there's a lot of float in the cleats.

My frameset was delivered from Peter Reich in March and I also bought a Zootr for friends and family to use when they visit. There's a difference in the frames. The Zootr seat tube diameter is 4mm smaller and seatstay diameter is 1mm smaller.

On the Zootr site they claim 9.9 kilograms; my stock Zootr weighs 10.9.