Both are abominations in the eyes of the one true manual stickshift.
Honestly though I have no idea. I gather they're preferable for supercars (doesn't the Buggati Veyron have one?) but I don't know if that's accurate or why that would be. Maybe sequential gearing is just easier at those sorts of speeds?
Well, Clarkson doesn't seem too enamoured of them. But, not being able to drive myself, apart from one or two lessons when I was 16, I think automatic is just lazy, and the the engine sounding like it was over-revving annoyed me, so count me in on your holy war for the One True Manual.