The determining question for whether or not it's the same is this: Are you the physical matter of your brain, or the electricity running through it? In the first case, sleep isn't death. In the second case, it is. I would argue that you're closer to the electricity than the brain matter, since an unpowered brain is how we define death.
But REALLY it ultimately doesn't matter, if you think about it. An exact clone of you created after any kind of destruction of consciousness is no different than the original you had the destruction never occurred. We just intuitively really do not like that idea.