... no likelihood of the brakes overheating the rims and blowing a tire.
Hans, all your other points can be argued, but I agree a disk brake won't blow a tire. Though I've met two people who had blowouts on long/steep descents (one of whom was riding a loaded bike), I've never personally blown a tire, although occasionally I have to think about it and change braking behavior to prevent it. As to the rest, it's a matter of taste. Properly set up brakes of almost any kind (cantilever, caliper, or disk) give good control on descents. I've read accounts of disk brakes fading -- after all, a rim is just a large disk, and it's possible to overheat either.