I will probably avoid discs for the time being because I don't ride hard, or in the rain. Plus, for new bikes equipped equally, the one with discs will typically cost more, and I am on a tight budget.
My rear wheel doesn't lift when I brake with V-brakes, but then again, that is because I shift my 300+ pounds back when I brake hard... I do typically skid the back under hard braking since it is almost at the point of lifting, so I think I have the ideal setup for a fast stop now. This could well be because I can squeeze pretty hard.
After more bikes with discs hit the used market, maybe I will have to learn how to determine which brakes are better than others and try a set. Until then, assuming I never gravitate toward riding in slop, I am happy with what I have.
I have thought of putting a front disc on one of my bikes, but by the time I replace the fork, wheel and brake, I could buy a decent used bike...