I have read a little bit about those and they get good reviews from the 6BT guys. Supposedly they will spool much better than an HX40. I would say if you are building a higher RPM setup with all the mods it would work great. If you are building a stock RPM slightly enhanced type setup, you would be disappointed. If you can get the fuel and air to it, then it will spool, but a stock engine will not make that happen. And, forget lugging with a load under 2K RPM.