My 98 ZR 600 EFI has been a fantastic sled! I have heard that other people had some problems, but not once have I in 5000 miles! Knock on wood! It is a little rocket if you add the D&D pipe/chip combo. Usually you can find a used pipe/chip combo relatively cheap as there are lots out there. If you do, make sure the chip is the right one for your sled, there were three. I also had the local dealer set up the clutch and it works very well. Love that sled. Will never get rid of it. Mine is the LE with the balck hood and it looks great......matches my new 800 EFI CC which was delivered today!! WOO HOO!!! I say go for it if it's in good condition. You will not be disappointed. It's light, fast and a lot of fun!
If you ahve any other questions let me know and I will try to help you out.