I recently sold my Bianchi Carbon Cross Concept with cantis and plan to replace it with a Niner RLT when it arrives this winter. I sold the Bianchi specifically because of the want for disc brakes. The writing is on the wall - discs will take over, and I do agree with Pattersnap that often the early adopters of new technology are the test mules. In this case the evolution should be fairly quick as the mountain bike world has already done the majority of the "testing". Since I was one of those "testers" back in the day with the AMP disc up front and a Paul's LP out back I "get" the idea. The evolution has come a long way since the early '90s. Yes, discs will have better modulation but to me it is the fact that a disc is bringing your speed down from the inertia point at the hub. It's not that V's and cantis aren't powerful, it's that under some conditions their leverage from the ground to the brake is too much and locks the wheel up. If you're sliding your control is compromised. The disc will be more consistent regardless of conditions and will offer a better "feel" for bringing you down from speed. I recently road a 2014 Giant Revolt with the new Sram HRD700's and was impressed with their smooth and consistent feel. Didn't do any long braking descents but had to laugh at how little actual braking is done on a "normal" dirt ride. Obviously different routes require different amounts of braking but when I was focused on how the brakes were working I noticed how little I used them. I am going to use the TRP HY/RD on the Niner so that I can run my current Campy shifters, sort of a stop gap until the industry catches up!
Sun Summit South @ crankandcarve.com