When MLG did Tekken 6, it was actually pretty well done. But they had RIP handling the commentary, so that defnitely factored into the presentation by having someone that is articulate when it comes to describing what's going on in the screen while sounding articulate.
Example:
GM vs Knee
That doesn't seem better at all (didn't sit through all of it, only about 1/2 before YT decided to die on me).
Long periods of no commentating, not talking too much about the match itself, and lack of audience reaction (at least from what I got through).
Part of the problem may have been that I'm not too big on Tekken either.
Again, stuff like Evo commentary is the most hype ever because as others have said, the commentary is good (they talk about the game, the players, the match, and sound excited), the audience is there to make some noise, and of course the matches are excellent.
And it's a PG stream.