I ride my CXer with discs when its raining/wet out, tried my CXer with mini V's & get a lot of brake chatter when its slightly damp.
Might be that my wheels/brake tracks aren't broken in yet or I need to fine tune the toe in on them.
I prefer my calipers over my V's while commuting, but on the trail the V's rule for me. The disc are best in rain, & snow.
Giant Defy Dura Ace : Rip/Hammer-Specialized Allez Ultegra/105 : Recovery/Spinner-Specialized Allez Red : Trainer-Kona Major(Rad) Jake : Down & Dirty
Ok - problem solved! TRP Spyre, yokozuna cable, disk fork change. Significant advantage in the dry, no wet weather yet but will report back!
Hope it works for you. I know that the braking power of my Shimano Deore hydro discs and the dual pivots on my roadie (2300 sti/tectro calipers) are worlds apart. The mtb has way more braking power. In the wet its far better, in the dry its almost instant - but less modulation. This a flaw in the Deore range that got rectified in xt and better. In short, if it rains I ride my mtb. It will stop me fast from 30mph wet or dry. Difference between the duals pivots and the v brakes on my shopping/kid bike? Not much. V brakes bite a little sooner other than that they have about the same power. Both suck in the rain unless you dry the rim first. Coolstops made a big difference from the stock pads but still don't hold a candle to discs.
I set up my winter bike with mini-V's paired with 5600 105 brifters. Bike is a redline cross bike. I threw away the crappy pads that came with the mini-v's and put on kool stops salmon pads.
I think the braking is excellent and better than the Ultegra calipers w/swiss stop pads on my road bikes, particuliary the initial bite. The downside is that I have to deflate the tire to get it past the pads, mind you these are 35mm cross tires and a 23 or a 25mm tire would probably slide thru. that's my .03
Rode very wet with the disc - extremely happy. No noticeable difference from all the water. Conclusion - if you ride in the wet you need a disc at the front. Probably not at the back though.