Imho, since monks already suffer from MAD, this is only going to make it worse for them. It's yet another attribute you'll want to max.Because I'm wary of piling three attribute bonuses onto AC. If it's demonstrably not a problem, then it's demonstrably not a problem, and I'm perfectly okay with the idea that my wariness may be unwarranted. It's just a gut feeling.
IIRC, the prestige class is basically trying to make a monk/barbarian multiclass character viable. The AC boost will be necessary to pull it off.