Hi all,
The biggest issue is getting parts. I have a 1996 GTX and a 2002 GTX-4Tec. All parts generally specific to those models are out of production and out of dealer stock. You have to typically find used parts from ebay.
As pointed out, independent shops are your best bet with older machines or doing your own work. The dealers are not really set up to deal with the older stuff.
Jetskier