Board Thread:General Discussion/@comment-11276487-20130706160459/@comment-11296535-20130811202710

Eres - Mistress of Illusions wrote: At the cost of your invulnerability wearing out.

Plus, you don't lose or gain stamina/health/magicka while Ethereal. This shout allows you to lose and regen like normal. You do gain attributes while Ethereal.