I have nothing bad to say about my two Yamaha's . There a snowmobile :) Always, some good and bad ! For Trail riding I'm not sure I'll ever go back to a 2-stroke.
Case in point. The last picture show's a good variety of sleds. Missing a 2017 Polaris Axys 800 . Only two sleds had no problems the Brand new Ski doo 900 turbo and Mine. 2008 Yamaha Vector . We only covered 600 miles in 3 days . I witnessed 2 sleds come apart going less than 45 mph . One had 2300 miles and the other 950 . I guess with the winters getting worst and worst I'll just keep what I have and ride them.