I have Avid BB7s front and rear and am in my second winter with this bike.

The front brake is perfect, all the time. I've only had to replace the pads at about 5,000 miles. The rear one has had issues, most of which were solved by running the cable in sheath for the full length.

However, on the rear, the inboard (fixed pad) adjuster seized last month. I took the caliper off, removed the plastic adjusting knob and turned it with a pair of pliers. That broke it loose. I dribbled some Tri-Flow on the threads, worked it in and put it back on the bike. I'll do something more substantial in the spring when I can use my other bike for a couple of days.

I had V-brakes before. I strongly prefer the disk brakes and can't see ever going back on a wet/winter bike. The V-brakes used to collect slush and freeze open. That could be a real thrill in traffic. I also had to replace pads monthly, and replace rims in the spring. I don't miss 'em at all.