As far as i know, in ladder it increases move spead and health regeneration. the incread in speed can be done with speed scroll, and i don't see any particular advantage with increases hp regen in such a fast paced game. Besides, endurance aura increases move speed and attack speed, much more useful overall in my opinion.

i also wondered why vamp aura was only 450 @ the shop while command and endurance aura are 500. perhaps bond could shed some light on that.