what I miss about cantilevers:
Easy peasy wheel changes
(Disks require through axle and I need a wrench to get the wheel off, and if I hit the brakes with the wheel off, I have caliper troubles).
Supple front fork.
Given the high hub torque of a disk brake, stiff forks and a through axle are requirements. Bummer.
Ability to use the wheels I've built up over the years.
best part of disks: Lots of flexibility in which size tire I use on the bike.