Guinness is not overrated: it is what it is. What it has that other stouts do not have is a fantastic marketing campaign. Their marketing is BRILLIANT! That does not make it overrated in the least. They never make the claim that they have the best stout. Stout lovers do not even say that it is the best stout, however I can tell you with certainty that it is very difficult to duplicate, and that is not true of a mass produced commercially marketed beer such as Budwiser.
Genesee Cream ale is some awful stuff as is Mickey's, Hamm's, Labbats, Molson, Moosehead, Yuenglings, Olympia, Lonestar, Pearl, and Sam Adams cherry wheat. Blech!