There is no maintenance on a CVT until time to replace the belt. Yep that sucks on a SxS as there is a lot to remove to get there but I check mine at around 1600 miles, normally replace with a new belt and save the old one for a spare if in good shape and so far all the CVT machines I have worked on still had good belts at that mileage. My only concern with auto-clutch shifters was the clutch was using the same oil as the engine and allowing the clutch residue to mix with the engine oil cant be good. Otherwise those were nice to be able to pick the right gear for your needs. However with the CVT just stab the gas and go and the engine always stays in the proper torque range unless your doing serious hill climbing or plowing snow then low needs to be used.
When I looked at the Polaris SxS models I had your same concerns with the front suspension and I do know of some folks having issues there. I was also not impressed with the welds on the frame sections where they join, not very uniform means less strength.
Actually I found those same issues on the John Deer models as well with the poor looking welds. I also made it a point with the dealers that if I was not allowed to look them over closely and take a test drive I would take my money elsewhere. Being a 65 yr old guy they knew I had the money to pay for it and was not some kid out shopping for joy. Only one dealer refused to allow be in the service area to be able to look them over very carefully....and yes I walked out the door! With that said, The dealer for the Kymco went absolutely overboard to allow me to look at anything I wanted. Don't know if they are all that way or not but this one was. I went into the shop where they had one getting service, and I was allowed to get in, crawl under, take things apart to look inside, what ever I needed to do. Then to top it off, when I told them I wanted a test ride they gave me a 450i camo and took me to their test track with hills, mud, sharp turns and decent straightaways and said try it out!! After a 20+ minute thrill ride on their proving grounds I went back and put a deposit on the red unit they had in stock. They were the best dealer experience I ever had buying anything. Don't know if others are that way or not, but these people sure were friendly to the buyer.