Like most things concerning setting up a jetski people, don't want their hard learned info put out but here are a couple of insights. The thin long blade flexes more to operate even more like a variable pitch blade. The longer blade grabs more water and loads the pump better. BUTTTTT------ Price is a little more. They can not be welded up if you mess it up or at least that was told to me by Impros, so run once no fix. They don't like to be bent and stay that way for too long, and most importantly they don't tune in with correlation to your regular pitches. You can not run a 10/15 then get a 10/15 lbtb., not even close. Every ski using one of these is its own build and tune. This is why if you get a top tuner to install one its not cheap. Most people complain about one impeller, how about trying two or three-- time and $$$$ If you can't tune a normal impeller then this is not for you. It is a true high end thing. My statement is not a slam on anyone here, it just is my experience of watching some of the best, tune in pumps. It should be the last piece in the puzzle and I think really only for competition, where that little extra does matter.
