I have to warn people when they ride my hybrid as besides having reversed levers the XTR cantis provide some massive stopping power which some folks may not be ready for. I use it for towing an 8 foot trailer that has had as much as 300 pounds on it and never found the braking to be lacking.

Have ridden a lot of single track and off road and used to run a front disc and a rear V which was an excellent set up... the modulation from the disc was excellent.