This is the popular saying
"Everybody wants one, until they get one."
I believe that was @JSNate's experience on pwctoday.com
So I bought one because I preferred riding the 550sx narrow hull and the X2 wider hull, but really didn't get a kick out of the SN SJ which has a hull width in the middle of the two.
I now know that I like narrow skis and wide skis and not really skis in between. But that is probably just me at my particular level of relative inexperience.
It is not a stable ski. The 550sx is a more stable ski if you can believe that. It is also not as nimble as a 550sx. It would not be a good surf ski for me. I would want a wider hull for that. It is just different. It was an attempt to make a powerful 550sx, but when it was introduced the buoy/slalom racing world had already passed it by with the 750 series. So only 1500 were made and they were only made in years 1994 and 1995.
[If you get one, you will need to immediately replace the stock hood latch (near the pole) or you will sink the ski. Talk to JetManiac about a Cold Fusion latch.]
However, for river and lake riding, it is pretty dang fun. It is the ski that I am currently riding. It has the power to pull you out of a leaned turn. In contrast, you had better have good balance with the 550sx because it doesn't have the power to roll you back up if you blew the turn by leaning too far inside. So, you will have to learn to ride it. I am still learning. I can slide it a little. I haven't done a 180 on it yet, but I think is coming this Summer if they open the river for riding. There is a reason the designer (who I believe was the designer of the 550 - Scott Watson?) made the raised pivot pole bracket. My guess is that it is to provide more leverage on the nose, but I don't know and I have never seen an interview with him about his design intentions. I would love to read an interview if anyone has one.
If it is a good ski and if it is a good price buy it. They generally go from $3k to $4k in good shape. So, if you treat it well you will get your money out of it if you sell it. The good ones are rarely sold though.
Would it be better than a 400/440/550 hull with a Yamaha 701 in it? I don't know. Hopefully I will get close to finding out when I put a Yamaha 650 in a 400 hull. The FX1 is a larger ski than the 550 to float the weight of the larger engine.
http://www.pwctoday.com/showthread.php?t=72880
https://en.wikipedia.org/wiki/Yamaha_FX-1
https://www.facebook.com/YamahaFx1JetSkiClub