(Original Review, 1992-10-25)
I feel uncoupled.
Who knows for certain: their inner experience of sights, smells, emotions, and the rest?
And this is why I often find the discussion frustrating; from my reading of his work, Dennett has never denied the experience of being conscious. What he is saying is that if you create a zombie doppelganger that resembles you in every way then the "zombie" will by necessity be of such complexity that it gives rise to consciousness. And it will do so from normal, physics-obeying, materialistic processes. It is in this way that we are all the zombies of the thought experiment - not that we are all empty machines that experience nothing.
If you're into stuff like this, you can read the full review.