I'm ashamed to admit that I had to look up pictures of the original set to see how the scoreboards were different.
Regarding at the set of the live show, if you look only at the game board set piece (as if it was standing alone), I think it's more aesthetically pleasing to have the families' scores centered in relation to the survey board, rather than sitting at the bottom of it. The only advantage of moving the families' scores lower is so you can get a tighter shot of the score and the family together. And since the live show isn't being broadcast on TV, why not go with the design that looks more pleasing to the eye when you're sitting in the studio audience?
(Next question: Why does the current version of the show split the difference?)