I had a 2000 and a 2003 500XCSP. Both of the sleds were good runners and would get 140 miles out of a tank of fuel on hard packed trails. I cleaned the valves every 1000 miles and used synthetic oil. The only problem I had with these machines was the ignition coil broke down in snowy conditions, but once I sprayed the coil with high voltage paint; the problem was fixed.
Good luck on your choice.
John.