I haven't really heard any Mudvayne since Lost & Found as well. But I def enjoyed them.
as for Korn, I'm one of the weird ones who doesnt really like their early stuff, their first 2 albums or so, and then in the middle, they made GREAT records, up until i think Take A Look In The Mirror, and then after that they dropped off again! I say I'm weird for that because I know most people hold the first 2 albums as classics, and after that they turned to shit. I think the first 2 are good, but around i think Issues was when they hit their stride in my opinion. But their last few albums have been real lackluster.