I don't think it's that simple Tarnak. From what I've read, some DDs get the MP while others get the HP. BST, for example, gets the HP+3%, while THF gets the MP+3%... wtf?
*EDIT* New info: It looks like the latent is determined by current job level: odd level jobs get HP+3%, even level get MP+3%. Sorry, endgame mages.