You are right about one thing, maybe weapons have moved on, but the M60 was the most underrated weapon of the VietNam War. Versatile and reliable, as many a door gunner from the era will testify.
I saw an article yesterday saying the M60 was the most iconic weapon of the Vietnam war.
Re the .50 cal, it would be interesting to know the current doctrine about its use against personnel. It seems to get a fair amount of debate on the interwebs based on a quick scan of Google search results.