The way the assymetrical case is done, the way the crown is so elegantly protected, that and the monopusher got me first.
The next heart tug came from the expanse of bridge plate (not sure about terminology) -- I am just a sucker for a flat expanse, like we see sometimes in breguet or LF, which always reminds me of pocket watch movements. I love manual wind, and big strong bridge plates provide a feeling of solidity contrasting with the delicacy of the timekeeping organ.
Also boy oh boy, this watch is in gorgeous shape!