I just wish to state that currently, stealth is completely broken with rogues.
I have cheesed my way through all the difficult content with a bow, and a vampire rogue.
He could sit a mile away up high and kill everyone in the room, without being spotted.
I combat he could just stealth and be unseen no matter where he was, and kill everyone. Just by shooting, rentering stealth and shooting some more.
Major problem with stealth is that the enemy just freezes, and does nothing to counteract my character. They just stand there.
Either they could try to reveal your character with force, light or something else. OR they could simply go all the way over to investigate.
Though most of the time they would not see my character either way, because he always wins on stealth rolls.