I am running the Snow stage 2 with the same nozzles as yours (2x 625ml) and it has never bogged on me at wot. The only time it bogs is when I am not at wot but making about 25psi just cruising up a pass or something then it will buck. I have it coming on at 15psi and full at 30psi. I havent seen any cooling effects but I did get an extra 63hp.

 

Sorry for getting off subject.

I wouldnt buy one unless you can get a used one since new they are way expensive. If I had it to do over I would make my own. If you make your own you can route it different as to not interfere with pump access.