my only mtb is a SS ecr with 3" knards on 50mm rabbit hole rims
it is a "touring" bike, and that is my intended use for it, but for the past 4 months ive just been tearing up fairly technical local singletrack on it and its loads of fun.
i dont find it to be any slower than my road bike, and as mentioned it just steamrolls over everything and has stupid amounts of traction. i can run <10psi with the tires set up tubeless, no need for suspension.
a krampus with a fox float would probably be absolutely invincible and 90% as capable in a touring capacity