This thread is showing me that it's a real shame we never got a fully battle-tested version of Password to enjoy, with the best of all worlds coming together in one format. We all clearly like a lot of things from both of these versions of the show.
These days, I'd have to give the edge to Password Plus. When I come across it on Buzzr, I often stay for the entire episode or hour, whereas I frequently don't stay for Super Password. By and large, the guests on Password Plus take the game seriously while still having lots of fun. That said, when my college classes fell around GSN's then-daily hour of SP, I was really enjoying the groove they were in at the part of the run -- 1988.
But yes, still lots of stuff worth tweaking on both shows. I imagine the Alphabetics penalty came from a good place -- they didn't want celebrities costing people THAT much money -- but in a world where Pyramid got by just fine without doing it, it looked odd on Password Plus. Ca$hword on Super Password is a great idea, but looking at the back of people's heads for the entire show as they turn to see the puzzle is not.
-Jason