It depends on who you talk to, personally I had a number if different bikes, my triumph 650 bonneville had a front drum that would squeal the tire when you jammed it on, a single disc brake has an inherited defect, if you pull too hard and lock the tire it will pull to that side if you are not aware and twist the handle bars in your hands (if this happens at speed you lose control of the bike and crash, I have had to force the handle bar to be straight. On a dual disc setup, you have way more brake than you will ever need if you lock the front tire under hard braking things go sideways in a hurry. Under optimum conditions (dry pavement) when you practice using the front brake together with the rear brake you keep the bike under control and can stop quickly. disc brakes have more stopping power, but it is also important what kind of tires you have on the bike.
disc brakes dissipate heat much better and will not fade as bad from repeated applications, drum brakes will get hot and fade after repeated uses, but for the average street bike this is not going to be a problem. Racing is a different story and has much different needs then street bikes.