He does sound like John you fucking idiot.
Thats one way of putting it lol. I really do think he sounds a lot like John Bush and I don't say that as an insult or anything I just really hear John Bush in his voice. I am sure some of it is that he is purposely trying to sound and pronounce some of the lyrics/words like John. He sounded really similar to John when he sang the Bushthrax songs when I saw him live.
But It was hard to get past his Phil Anselmo stage antics to actually even pay much attention to his voice, so I was a bid jaded. But all I could think when I saw them with Don Nelson was on vocals was "What the fuck is this crap, this is not Anthrax" It was hard watching Rob on stage instead of Dan Spitz (still is but i have accepted it), yet alone not having Joey up there... or even John Bush.. then you throw some no name Phil Anselmo wanna be guy up there and it was like watching a cover band