You must be talking about a specially designed racing automatic transmission (as in a Level 10 unit or something similar). Stock automatic transmissions can't shift faster than a good driver driving a manual transmission. You'd have to spend a ton more to get an automatic that would shift faster than a manual than you would spend on upgrading a manual and improving your shifting. Where do you think the name "slushbox" came from?
I'm not trying do to be a dick!, but all those with smart ass answers to my smart question,it makes perfect sense what I said, you can lower it maybe 1/10th of a second! It's true look it up. Hey how's that for a newbe question?