True, there are extreme conditions that will eat a set of disc pads in a day; that same set of conditions will likely eat a set a V-pads in a couple hours.
I have seen V-pads go south in a matter of MINUTES!
I just replaced my Avid BB7's this past winter; they had three years on them, in all conditions (road salt finally did in the calipers), and two years on the pads. THEY'RE still useable, and are stored as spares for my new brakes.
I will never ride a bike without disc brakes again.
Oh -- ceramic pads, $17/wheel.