I tried the new version. It's definitely improved. The jumping physics are still really wonky, though. The camera no longer shifts every time you turn around. Now you have to actually move before the camera shifts. It's a lot less jarring.
As a single player experience, it's great for a hack, but doesn't stack up well against any other official Mario games on the SNES or any of the great platformers on the SNES. Stage layouts are mundane and repetitive, but I guess it's short enough and the way that the Gameboy original was. Speaking of the GB original, I never loved that game. Someone brought it over to my house when I had a Genesis and he played Strider while I got pretty bored playing Super Mario Land. I guess the Gameboy was never my thing.
I haven't gotten a chance to try the multiplayer version of the hack, but I think the lack of scaling will mean that the screen is too cramped for more than 2 players.