I have the 2013 Apex se 128 with 12, 600 miles, so far all I've had to do at around 8,500 mile was change some bearings in the bogies and this year I had rubber coming off the 2 inside bogie wheels all others were good. This spring changed out bearings on the left side of the jack shaft and drive shaft. This year I also got my center shock rebuilt, will do the fronts for next year. In 5 years of hard riding never lost a pound in any shock. I put the DuPont sliders on at around 1,600 miles and they are still good with close to 11,000 on them they just stay right around 10 mm thick, can't get a 10mm wrench on them. When I put the sled away last week I pulled my track all the way around sitting behind with the back end up in the air and noticed it was falling apart so I will be putting a new ice attack on for next year. Oh at 8,000 miles I had to adjust the power valves to get them lined up, very easy to do, just make sure you don't get the cables to tight. Also put new slider buttons in the secondary clutch at this time. I also had to put new bushings on my sway bar, the left one was worn, right one still good, all others still tight. That's it in 5 years of 2,000 to 3,000 miles every year. I grease the suspension before each ride and blow compressed air in the clutches every second week as well as cleaning the belt, gets me away from the tv. Just before I put her to bed for the summer while I was running some K100 through the engine at idle I put my gloved hands over the exhaust and the engine stopped in a nano second, so I guess my donuts are OK, Might change them for next season, so that I'll know I'm good for another 12,000. It really has been an incredible sled. All my friends who bought cats and doos at the same time are on there second sled.