I have learned not to make a judgement on one bad review. I look for a trend. No matter what brand you go with, it is a big investment, and one you wnat to enjoy for years. I went thru exactly what you are going through last Apr-May. I read many posts and the appropriate forums. I decided on going with the Yamaha. Wasnt a right or a wrong decision, just my decision. Scarab makes a beautiful boat, as does Chaparral. Both have proven engines in the Rotax. My decision was based on several issues:
1. Warranty - Chaparral and Scarab have better factory warrantees, except in their promotion, Yamaha gave me 4 full years, bumper to bumper at no additional cost.
2. Jetboat experience - Though Scarab and Chaparral have been in the boating business for many years, they are relatively new in the jetboat arena. I believe Yamaha has been doing it for 30 years.
3. Single Manufacturer - As far as I know, Yamaha makes everything on their boats except the sound systems. So when it comes to service you have one company to deal with, be it hull, engines, drives, electronics.
4. Price - Although at first glance it appeared that Yamaha was the least expensive, with some research I found the Yamaha's prices were pretty much set, unless you find and end of year special. The others will deal....and the end result was the prices were all pretty close across the board.
5. Options - Yamaha has almost no options...their boats come fully equipped. This could be viewed as a disadvantage because you may end up paying for options you may or may not want. For me....I wanted pretty much all the bells and whistles, so not having to pick and choose made it easier.
6. Dealer availability - This was a wash....there are dealers for all 3 brands in my area. The dealer I bought from, however, sells both the Yamaha and the Chaparral. The one thing that had a huge influence was when I asked the dealer about comparisons between the Chap and the Yamaha, which were both their products, their answer was both were comparable in features, performance, and reliability, but bang for the buck, they recommended Yamaha.
I am sure some Chap and Scarab owners will chime in, and even disagree with my assessment and that is what is great about this forum....loads of info to make a decision on. As I said, these are the reasons I made my choice, and not a slam on any of the brands....they are all awesome boats.
Good luck, and no matter which you decide on, welcome to the crowd!