I own a 96 XP 800, they were given really good reviews by a lot of people and I admit, it was a fun ski to run for a couple of hours but then it became boring until the next day and was fun again for a couple of hours and was boring again. But lessons have been learned...the hard way. A little history of SD experience, the marine repair shop I worked in for some time had seen a lot of these SD jet-boats come in for repair. SD in general are maintenance pigs and they are money pigs too when in need of repair.
As for my lemon, I have come to find that the crank bearings they use are terrible, the cages on my ski's bearings blew to pieces 2 summers ago. When I separated the case halves, in between the bearings and the seals was a handful of cage material and all the bearings were tight together, not spaced out like they should be. Then there is the issue of the mag cup, the stator sits inside the mag cup and if you have bad crank bearings or ones that go bad, the excessive play in them allows the mag cup to scrub the stator. It only takes a few minutes to burn out the stator when this happens and now you're shafted to get the stator rebuilt as well.
The rotary valve shaft seals are famous for prematurely wearing out and letting oil leak past them and into the crank. Most people think this is a good thing, more oil for the pistons and all. The problem is, when you double up on the oil you build heavy carbon deposits on the rave valve. If the carbon plugs them up enough you have a very good chance of blowing the top end. But I think the ultimate slap in the face from SD...again from experience...their parts support.
If you've ever seen the new SD commercials they indirectly admit they design them to only last 10 years (if you even get that far) and stop supporting parts production in certain categories after the 10 year mark. As they say in the commercial..."every sea-doo is built to last a decade", what they don't say is after that ten years they discontinue production of such key parts as stators, crank shaft assemblies, CDI units or (as they call them MPEMs) and a few others. Again, found out from experience when I couldn't buy a new MPEM for my lemon in 2006 when they announced the discontinuation of these parts. They probably had a ton of these parts in their warehouse too but as soon as their computer database says NLA, all dealer databases say it and they cut you off at the counter saying sorry, good luck. I know someone that bought a 95 Sportster jet-boat and only wants a decal kit...they were told the same thing, NLA.
At least with Yamaha or a company like Sugar Sand whom makes their own jet-boats and use Mercs inside, you have a parts inventory support of 20+ years. Something to think about. And the jet-boats will clip dead heads. I watched the water police here in Ontario trash the bottom of a new jet-boat they had off of a dead head about 10 inches under the surface. I'd rather toast a prop than a fiberglass hull IMO.