Looks interesting.
One point: you might need to do some research about what weight your swim platform will handle. Our builder told me the design specs for ours was 500-lbs... of occasional "people" weight. IOW, not 500-lbs of constant dead weight.
I wanted a very generous margin of error, so we added additional struts from our davit system to the transom, to augment the swim platform's load-bearing capability. I don't see a way to add load-bearing capacity to that Hurley system... but it would perhaps be possible to beef up the capacity of the swim platform's itself in many cases, if necessary.
FWIW, our system currently uses a hand-crank winch... on a fixed mount... and I don't (yet) have any problems cranking our ~260-lb dinghy/outboard/fuel/battery aboard. If it comes to that, I can replace the hand-crank model with an electric winch, but that's not really my preference...
-Chris
