I can vouch for the 1997 GTX. Probably my all around favorite ski. It does it all very well. Handles great, nice stable 3 seater, good power. Mine run about 50mph on the GPS. Especially good ski for the ladies as it is easy to get on and off. I have many skis to choose from and these are our keepers. Love em' !!
97 GSX will be the most fun but really a 1 person ski, 2 is not really comfortable. Almost as much fun as an X4 but a little more stable and not quite aa easy to throw around.
97 GTX is a great 2 person (3 is cramped) cruiser or tow aki if you want to pull tibes etc. It can get a little boring unless you really need a family ski.
The GTS i refuse to own because i think they are the ugliest skis anyone ever made, lol. It will be a similar ride to the GTX with less power but very easy hull to do 360s all day. It will be the best on fuel and require the least maintenance though.
I had a 1998 GS that was a hella fun ski. The guy I sold it to said it hit 50mph which was faster than the 48 I got. Both speeds were using the GPS. The GS handled very well and has the 717 engine. Definitely a single seater but you can fit two small framed people.
It is all relative to your needs. I have a 1996 XP and I find it a bit too much but if you want to go full on hooligan that's your ski.
I'm not a GTS fan either and I really don't like any of the skis that have the rudder assist. They turn like crap and handle more like a boat unless I'm doing something wrong.
I'll second again my vote for the 1996/1997 GTX as the best all around skis with a reliable engine that is fairly easy to work on compared to the 951. If you like a little more grunt on the bottom and a few mph on top end the 951 will get you there. Good Luck !!
97 GTX is a nice machine. I can't give any opinion on the others since I have no experience with them. It is bit bulky but not as heavy as the modern rigs, tops out at 50 and rides like a Cadillac, stable and pretty nimble for it's size, plenty of room for two people, easy to work on. There's a lot to like.
I can't speak for the 98' GTS, but it looks like it would be slow with the 720.
96' - 97' GTX is a great well rounded ski, comfortable with a passenger and can reach mid to lower 50's. Big 15 gallon tank, can handle the chop very well, great for cruising distances, plenty of storage etc. Carb 787 is easy to work on and won't break the bank. It's not as tight like a GSX, it'll spin out fairly easy. Has reverse and neutral.
96' - 97' GSX is a fun ski, you'll get wet on it for sure, not as stable as the larger GTX hull, great as a 1 person ski. Unless the passenger is a small kid, it won't be comfortable with 2 on it. Big 15 gal tank, it'll go the distance, but can really cut up if you want to, digs in and pulls some g's. Carb 787 is like the 96'-97' GTX, easy to work on and maintain. Doesn't have a reverse or neutral, takes a little practice to dock with start and stopping. Little faster than the GTX, maybe 3-4 mph more on top end.
I love my 97' GTX, but I'm glad I added the 96' GSX as a compliment. Depending the mood or if someone goes out with me I'll take either. I prefer the 96' GSX because I can do everything, cruise a long time or cut up. Taking a passenger, like the wife, the 97' GTX.
I actually owned a GTS, it was my first ski can vouch that it lasted many years in fact it would still be around if I wouldn't have swapped out the fuel lines using faulty hose clamps (now I know to use zip ties). It would do about 40 but that was enough speed and felt good about the kids learning on it.
I was pondering the same question about a year ago . . . .
Many of the questions which were considered to select a suitable PWC, based on the usage expected in my case,
Stability of the craft on choppy water,
Resistance to rollover,
Complexity of the engine/drive, simpler the better,
Maturity/history of the craft/engine,
State of the engine (i.e. good compression or on the edge of a rebuild),
rider capacity, wanted a 2-3 seater (comfortably) to that it could be used to "legally" pull a tube or skier,
availability of parts, new and old for repairs,
ease of maintenance (plenty of room to work inside the engine hold),
storage space (ability to hold deflated tube, rope, towels, etc),
ease of maneuverability for docking, (ability to control thrust, neutral/reverse),
top speed (after all, isn't this why we have a PWC, "motorcycle on water")
lastly, the price . . . .
After looking at quite a few options out there I settled on a 1997 Seadoo GTX with the 2 cycle 787cc Rotax engine.
I did encounter a few challenges with the GTX I purchased, but was a blessing in disguise, as it was an opportunity to learn a great deal about the craft, leading to much more peace of mind during it's use!
So, although I have not owned all three, and do not have direct experience with the GSX & GTI, my vote goes to the GTX! (mine looks just like the ones in the post from etemplet)