You're right, that one is more impressive, but as I understand it that version of tetris has more forgiving physics than the NES version, and he's using a more ergonomic controller, so I think there's a pleasing purity about maxing out the famicom edition.

Also to be honest that second guy comes across as terrifyingly superhuman. The NES one actually looks like something I might actually be able to eventually do with practice, and is therefore more engaging to watch.

The physics are more forgiving to make up for the fact that gravity (and as a side effect, vision) can become much less forgiving. At that point, the game's much closer to DDR or Rock Band, except with a much less readable note chart (the well + next 3 pieces). You have to think about where each one belongs and have your move ready before the piece drops; instead of just one piece you have a small amount of time to work with.

The new Tetris versions also use a friendlier and not-so-random number generator. Basically, it generates a random permutation of the seven different pieces, deals those, and then generates a new permutation. This makes the game much more predicable. You can see the player make clever use of the hold area in anticipation of this cycle and that's pretty entertaining to watch.