If Stealth reduces aggro range, it doesn't do it by enough to be of any use to anyone subbing NIN. I run around as a 50 War/Nin all day, and I've got a train of ******* EP on my ***, beating me in the back of the head with sticks and arrows. Sure, the damage isn't TOO much, but at 50 it becomes considerable.
Stealth needs to either have upgrades, or be done away with completely, adding something more useful for NIN and /NIN into the mix.