Is Rocky Marciano one of the top ten best heavyweights of all-time?

I have read about and heard of more than a few boxing experts and a number of critics who have all dubbed Marciano as unworthy of being in the top ten best heavyweights of all-time list. The usual claims are that he never fought someone with the same punching power, that he never fought any prime fighters, that he was in an era where there were few good black fighters, that he lacked most of the skill that make a great heavyweight, that he really lost his match against Ronald LaStarza, etc. At the same time, just as many people say he is in the top ten. He is the only undefeated heavyweight, he beat the best of his time, he had an akward style that helped him win his fights, he never was set on the back foot and he had possibly the best single punch knockout ever. Is he or is he not worthy of being in the top ten?