Lol, most of these acts have watered down over the years.

Mudvayne is only happening because Hellyeah is mostly done after Vinnie Paul's death. Not sure how they'll be, if they'll be anything.
Korn has been sucking.
Slipknot is a little unstable right now.
System of a Down isn't really doing much and Serj Tankian hasn't been that interested in rejoining the band.
Deftones is solid.
Limp Bizkit is a has been, also fuck Fred Durst.
Disturbed is just okay.
Papa Roach is so-so.
Static-X is just a tribute act these days.
Drowning Pool lost a lot of relevancy.
Mushroomhead seem to be doing fine.
Alien Ant Farm is still doing something but they're so-so. One hit wonder.
CrazyTown is more or less dead.
Ill Nino is just up in the air.