Sea-Doo engines tend not to last. I don't know what specifically goes bad, because what I usually hear is, "it blew up." I would guess a manifold, and resulting catastrophic damage before it slows down, but I suppose people could be cracking the blocks. The motorcycle companies are pretty good at this high-revving engine thing.
Nothing "comes" with a trailer, but it is easy to get one included. When I bought my Kawi a few weeks ago I got a discount on the boat, a free Triton trailer (which I like a lot), a huge discount on the extended warranty, and a few other freebies (towards accessories).
As for max performance starts, remember, that doing that a whole lot is a good way to cook the engine. Besides, when you are out riding, maintaining a good speed is a LOT more fun than coming down from a plane and starting over.
I am not surprised the Yamaha is a little quicker than the Kawi, based on displacement, but you should ride a NON-supercharged and see what you think, then find out what the maintenence differences are for the supercharged. I personally don't like turbo- and superchargers, but that is left over bias from the '80s when they all sucked.
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