I think we really need to differenciate dark and muddy here, while factoring in guitar, amp and cab.
I have no personal experience with the MM, but from what I know I can see people refering to it as dark.
While if people were to find that I would suggest lowering the Pu about one mm and raising the pole pieces by the same value and see where it takes them, even that might not always take them to a point where their ears do not feel like it is dark sounding anymore.