Imo, all three are about the same, and the usefulness are small. Still, you guys are really whining to protect the only real "armor" you can wear. It does nothing at all for you but make you look good if you like the armor. Even if its only 8 mp or 2 mind, it still does SOMETHING for you, unlike the breastplate. Yes, you can wear what you want, but don't go on lying to yourself that the money you spent on it was worthing anything but appeasing your sense of style. I remember a pld who chose style over good stats, and I call people like him idiots. Yes, he was a pld and it mattered a bit more there, but it's all the same. That's why people are willing to pay 250k for 8 mp and 1 int. As fire said the extra def will NOT help you much, if you feel shaving off about 5 def as he said, by all means do so.
I'd still rather see a whm wearing a seer's or bishop. And should I give enough to ask why they are wearing bishop, and they have the nerve to tell me "So I don't die." or "So I don't get hit as much" I find it an insult to the tank, who've you have better known to suck already. I won't think anything if they whip it on afer everyone can see the tank sucks. And people who say "Cause it looks cool man" I just roll my eyes at them and laugh. Anyways, it's an opinion and you can wear whatever you want, as useless as it is.