Martial arts doesn't seem to give the +1d4 and expanded critical range, and Defensive martial arts doesn't give the +2 AC or 10% concealment. Atleast, it didn't for me.

The DM's have said that it does work and frankly i've tested it and it does not work... with a dexxer monk 1d8 dmg the feat is supponsed to add 1d4 but my minimum damage is still 1 and max 8 so it is confirmed that it does not work.

not sure whether you need to have gloves equiped or if it realy is bugged.

the martial arts feats are broken, the one that applies the damage and critical range actually equips a fist weapon to your character that has the following stats

Martial arts
1d4 damage base
keen
massive criticals (i forgot how much, but i think it had this)

not sure what to say about the defensive martial arts, it is probably an issue with the type of AC it gives, most likely deflection which does not stack