Sorry can't comment on yamaha jetboats, never been in one. But yamaha is a name I trust, i have a 30HP outboard, have had lots of their crotch rockets, home audio equipment, pianos etc. I would expect the same quality from their boats.
My real advice ... your likely spending north of $40,000.00 all in (not sure about yami pricing though). In my world that is a huge chunk of dough and nothing is worse than buyers remorse on something that substantial. Test drive both and take your time in deciding. Post back what you end up with. AND PICS (but only if its the BRP flavour .. lolz) jkn' ... good luck and any more questiosn pre purchase just ask.