Why do you say the Spotz is much faster? Am I missing some info from somewhere?
Here are the results of the 2012 kite hydrofoil world cup (first one ever held): http://www.kiterace.fr/uploads/Result%2 ... 012Men.pdf
First and second place were Taaroa. I do not know what boards everyone else was riding, and I think a lot of race foil have only come out after that event was held. It is hard to tell which foils are fastest today, but back then it seems like Taaroa had the best combination of speed and control-ability (or maybe just best riders?) to take top two places out of a lot of riders.
It is sorry the 2013 world cup did not take place. I planned to go. It would have been in Dubai round about now. I'll have to save up for the 2014 one. But I also want to upgrade my foil, and that will be quite expensive.
It is hard to judge how good each brand of foil is. I wish there was an objective way of knowing which foil to choose for the type of riding you want to do. I am looking for a faster foil, but not for better upwind, but for better control when going fast down the line on big waves/swell. I think I need a foil which is not too high aspect ratio, but has very clean lines (low drag) and is controllable at high speed.