Most overrated? Without question. I remember having this discussion with my dad back in the late 80s. My dad and I were arguing over whether Tyson was good or not. I took the stance that although Tyson was a skilled puncher and a great knocout artist with speed, a great boxer he was not. My dad didn't think so. At the time Evander Holyfield was a light-heavy weight, a boxing machine. He dismantled everyone that was put in front of him, a true boxer. I thought that even then if Evander and Tyson fought in their prime, Tyson had no shot. Soon Thereafter, Buster Douglas showed the world that Tyson was a myth, most of his early bouts (pre- title) were won before the opponent got in the ring, you would see some of them shaking in fear.
Tyson had noone to fight in his prime. Buster Douglas, a journeyman at best, took tyson to school. Tyson's trainers never taught him how to box. He was always short for a heavyweight, therefore his best and only chance was brute force (which he could deliver) and speed. Throw in the intimidation factor and you've got yourself a world champion (I'm sure his borderline insanity helped a bit too).
I'm no Roy Jones fan but I think that he could have beaten tyson in his prime. Any of the great heavyweights of the past in my opinion would have killed Tyson as far as I'm concerned. Tyson doesn't rate in the top 10 heavyweights of all time IMHO.