These are good for macroing in before your voke. 1 macro to equip all your +enm gear, voke macro, 1 macro to equip all your regular gear. You blink a bit, but all that enmity + voke on that hate spike helps.
These are good for mnk and sam I think only for /thf lv60+. Throw these and other enmity gear right before a SATA and it's a little boost for your trick.
Granted some pieces are better then others, like these hakama would be decent for melee (during the day), whereas the Arhat's Gi would only be useful for 'voking purposes (granted all of your shadows are up).
I want them! I'm not sure how useful this will be for a monk or sam, but for ninja, this certainly seems like the way to go. Perhaps pop the ninja hakama back on at night.