This ring is lv. 50 enmity-4 for just 8k IS, and the recover HP thing could save you some day if you're out of MP and poisoned and your HP is ticking down to 0. ROX0RZ! You can get this amount of IS from 8 Besieged or from 8 merits in TOaU zones. Amazing for any mage (or softy melees) job 50+.
The besieged: VIT+10 thing is pretty useless unless you're a Paladin 75 and plan on provoking, but it doesn't hurt to have it there either. ^^