I guess it's all subjective. I mean, there's crazy fast, there's crazy creative (with weird timings and swings and such), it still evolves as far as I can see, but you can never predict when the mainstream drumming goes sideways. Personally, I always liked Lombardo for his own manic style back in the day. He never sounded like a machine, but like a man possessed, with fills that would practically fall off the edge of the kit, sorta like Bill Ward before him. Also really loved Biohazard back in the day; Urban Discipline was one of the few albums that had me sold on the drumming, solid, but with some groove, very not-tech. As far as peaking goes, I think it's just a thing that evolves. I remember talking to a friend decades ago, speculating how anything could get heavier than Hell Awaits, but at this point, I don't think it's so much "how much heavier" as how will the sound evolve into something else altogether different, but still punishingly brootlz!