For my part, what I prefer is when MAD is the result of making an elective choice, rather than being stuck needing to max a bunch of things that you just can't do that with.
So, for example, some folks were...not enthused with the design of the 4e Paladin, but I actually kind of liked it. Because you could choose Strength or Charisma as your main stat, and then either the other of those two (versatility but weak riders), or Wis or Con as your secondary stat--and some builds even wanted at least a modicum of Dexterity to make the best use of swords (specifically, heavy blades.) Most of these options were quite viable, they just restricted you to a smaller set of worthwhile options, rather than being necessarily "better" or "worse" at their fundamental goals.
A Str/Wis Paladin would have solid riders and be good at smacking things, but would consequently be a bit weaker at the actual, direct Defender role--verging closer to a well-defended Leader with good offense, or even a support-heavy Striker with good defense. A Cha/Wis Paladin, on the other hand, could make one of the best non-Cleric healers in the game, and with the right PP could actually be a full-time Defender and Leader. Going Str/Cha, a "Balanced Paladin," would lead to getting the pick of the litter for powers, but you'd have relatively few uses of Lay on Hands, and your rider effects (which usually are based off of Wisdom or occasionally Constitution) would be relatively weak.
Those produce actual choices, rather than the pseudo-choice of "be strong or be sucky" or the even worse "choose which way you want to suck." That's interesting, engaging design, which enables varied gameplay--a high-Strength, high-Con Paladin is going to feel different compared to a high-Cha, high-Wis Paladin, to the point that you may genuinely end up having starkly different gameplay experiences despite playing the same class.
So, if (and only if!) "MAD" means "there are many ways to succeed, but none of them will make you successful in everything," then yes, I'm all for it--that creates real gameplay variety. But if "MAD" means "there are many ways to fall short, and no matter which one you go with, it'll hamper your basic gameplay," then no, I am absolutely opposed.
I find that most editions of D&D that pursue MADness in classes end up being the latter, not the former.