Personally, I don't see the Sphinx as being a faster position than drops. I think the more aggressive Sphinx position with the hands on the "tops" as opposed to where the hoods would be, is more of a relaxing position, taking stress off of the arms, shoulders, and neck and lowering the heart rate a bit.
That position may be illegal now, though, per the UCI.
EDIT:
This may be illegal:
(I know this guy is using clip-on aerobars. But just imagine him resting his arms on the "tops" without the clipons. I can't find a pic of a person doing that, so this is close for illustration purposes)
I think this is still legal (and I think this is @
queerpunk / queerpunk):
