For anything that my opinion is worth...this is a vastly superior game to traditional Zendo.
Speed Zendo sounds great. However, I really dislike the timer rule. I'd like to see some more elegant way of managing guesses. Also, since there's nothing like Mondo, this game might feel even more like a "multiplayer puzzle" than standard Zendo does, but maybe that's not a big deal. I've tried to think of ways of re-introducing something like Mondo in order to replace the timer rule with guessing-stones, but everything I've come up with seems like it would interrupt the real-time flow of the game too much.