I've owned both CF Moto and Polaris and wouldn't steer anybody away from either machine. HOWEVER, there are going to be some issues no matter what you buy like previously mentioned. Like I've always heard: "if it's got tits or tires; it'll give you trouble".
So here are my complains with each:
CF Moto -
1. Not friendly to perform routine maintenance. It's not like it's impossible, but it's not nearly as easy as it should be to get to the air and oil filters.
2. The comfort/ergonomics need some refining. If I were to change the cockpit I'd increase the legroom, make the seating angle more laid back and lower, and finally move the gas pedal so it's more comfortable on the shin muscle.
3. The aftermarket support has made leaps and bounds, but you're not going to have access to the amount of accessories as some other brands.
Polaris -
1. Money pits. Everything about my RZR costs more. Initial cost, maintenance items (if you use Polaris brand), parts (again if Polaris), and the availability of accessories just makes things more tempting to spend money lol.
2. Quality Control. The price of these units in correlation to the quality of some of the parts is almost criminal. I bent an a-arm the first weekend and replaced it with OEM (shame on me) and bent it again a few rides later. Now I've got SuperATV high clearance forward arms. They weigh in at almost 25 pounds heavier than OEM if that says anything. The voltage regulator is known to be a widespread issue as well and there haven't been any recalls to my knowledge.
3. Not backing warranty claims and work. I think this is partially the fault of some dealers not going to bat for customers, but I've seen too many cases where people were denied warranty work for whatever reason. I'm sure that some are legitimate denials, but I feel like there are too many cases where warranty claims are denied.
Whatever you choose just enjoy it, maintain it, and do your part for the off-road community so we can keep doing what we love to do.