I use one of these as a 63 BLM when the party has a NIN tank.
I use an INT+ setup (for PLD tank), and an enm- (for NIN), and this + Healer's Earring + AF feet (vice Hume RSE feet) gives me -3 emn (to add to what the rest of the AF gives).
I have to trade 7 Int for the emn-, but since my nukes don't hit quite as hard, it's easier to cast the tier III elemental spell appropriate to the mob.
So, by itself, it's not great for the enm- or the MP+, but good for certain gear setups.