Heck, I watched it yesterday at the local CAS practice match I attended. Slip hammering IS slightly faster in the fact that the hammer does not touch the sear, and the trigger does not reset then release again, in the hands of an expert. Having said that, I personally don't use it, I am not out to win any belt buckles, just a fat old man having fun, and I'd probably screw it up.
P.S. Practice match means you don't have to dress in costume, in case you were wondering...you probably weren't.
