Do you get the achievement after you kill Elijah or after you escape the vault? and also whats the quickest way to escape the vault?

You have to kill Elijah, use this http://www.youtube.com/watch?v=gVfPfhBAVqA . Lower the difficulty too if you want it to be easy.

The second playthrough I had a higher repair, I disabled all holograms in the coridor right before the vault.Made it easier to run past them with no worries.Managed to drop gold bars near door way.Then rerouted the sentry guns to target elijah.And looted body and ran.But thinking back it would've given me more time to just let the sentries finish him off while I ran back through the hallways.would give you a head start.