I'm almost certain that, in a dark room, with all other things being equal (heads, sticks, player, etc.), I wouldn't be able to tell a Clubdate from a Downbeat...and certainly, in the context of playing either kit, in a band, I wouldn't be able to differentiate one from the other.
To Ludwig, it was just a matter of economics. There was no sonic research going on that drove them to make one model with more lugs and another with fewer lugs. It was just that the model with more lugs, cost them more to build. The consumer's perception was that, if one model cost more than the other, then the more expensive model was the premium. In retrospect, the Clubdates were likely the better sonic design.