Don't buy the Merc powered boat. Seadoo no longer supports them, and they are expensive to fix.
To be accurate: It doesn't matter that "Seadoo" no longer supports them.
The Mercury engines ARE supported by Mercury, like they've always been. Parts, service, etc. are widely available.
Parts for the Mercury-powered Seadoo boats (hull, fittings, etc.) are available from Seadoo as well.
In other words, the pre-4Tec boats are quite well supported. It's just that SEADOO dealers would rather sell and service the newer boats because that's where the money is. Can't blame them, but it doesn't mean the pre-4Tec boats are a bad buy.
See for yourself: Check your Yellow Pages. See how many "Seadoo" dealers are near your house. Then see how many "Mercury" shops are nearby. Chances are you'll find there are a LOT more Mercury shops. Every little lakeside community seems to have a Mercury shop, but sometimes you have to drive a long way to find a "Seadoo" dealer that handles their boats.
For some reason, it seems many people forget that having engines made by the same company as the boat (seen in small jetboats) is the
exception in the boating world. Look at virtually every non-jetboat out there - fishing, wakeboard, waterski, cabin cruiser, all of them - and you'll find the engine is made by an engine company while the boat is made/assembled by someone else. True for everything from little outboard fishing boats to the largest cruise ships and navel vessels.
True for aircraft, too: Cessna, Boeing, Airbus, etc. buy their engines from engine companies like Lycoming, GE, Rolls-Royce, etc. Would you skip buying an airplane because its engine wasn't made by the same company as the fuselage? Obviously not.
Finally, as often mentioned here, the Mercury engines in Seadoo jetboats are nothing more or less than Mercury outboard engines. Their serial numbers even start with OE###### (
Outboard
Engine). They have the same parts, use the same tools, and are supported by the same technicians at the same shops as Mercury outboards. You can hardly swing a dead cat without hitting a Mercury shop that works on outboards, and that means you've found a shop that can work on your engine. As noted above, there are a lot more Mercury shops than Rotax shops.
Hope this helps you make an informed decision. Report back!