I'll get in on this discussion.
My first ATV I personally owned was a '96 Sportsman 400 2cycle. My next was a '99 Sportsman 500. Then another '01 Sportsman 500, then (2) '04 Sportsman 500 HO's. My '99 and both '04's had the same problem- the slack in the front diff output shaft caused excessive wear at high speeds over time in the strut hubs. All rebuilt under 1000K, and the '99 bombed shortly after its repair causing me to sell. Also, all units would be in AWD randomly at times without engaging the switch. Needless to say, in '06 I went to a Yamaha Grizzly 660. My younger bro got a Kodiak 450 IRS, and my older brother eventually stepped up to the Grizzly 700 EPS. Awesome units. BW the three of us we had zero issues over the years we rode them. They did not float like a marshmallow either, which I loved. Most applaud the Polaris ride, but not for how I ride. Good for the mudding crowd I guess, but not for technical trails. The Yamaha units would accelerate better and had better response due to their initial punch not being absorbed by the marshmallow rear suspension. It's great for putting around the farm, but when your IRS is inverted with two people or a decent load on the unit, that 10" of travel only leaves you with ab an inch of upward travel BC it squats so badly. Even when riding solo, the rebound is horrible, and when climbing steep rocky hills the weight of the unit squats the rear down where you truly only have about 7" of clearance. You can tighten the preload, but after a few months you will be sagging again. My Uncle's Ranger 700 (with the awful McPherson strut setup) does the same. My cousin's Ranger 800 does it as well. However, I was thrilled when Polaris introduced a dual a-arm front as an option (again, I cannot stand the cheap McPherson strut setup). I was so thrilled, I went against my better judgment and purchased a RZR 570. "Sport tuned suspension" sounded great. Owners seemed pleased with the RZR lineup. The new ProStar engine and upgraded clutching system mated to the ProStar was Polaris' fix to their past, sloppy, cheap golf cart clutch system. They finally made a unit ready for abuse. I plunged in. I had two warranty claims in 3 months, and I sold it. Even though Polaris went with dual a-arm, I learned the hard way they still chose cheap components. The bushings are so bad, they wear at a rate that is embarrassing, and if any Polaris owner would jack their front end up they could move their wheel/hub 1/4". That slop causes other components to wear such as the ball joints, tie rod ends, and diff bearings. That is Polaris' main problem. It is a cascade effect where one component wears out followed by another and so on. There are plenty of fixes such as new coilovers, Delrin bushings, etc, but we are talking apples for apples, rolling off the showroom floor, OEM quality- not aftermarket improvemts. I have patiently waited for Yamaha or Honda to come out with a side by side unit that would fit in the bed of a truck, and Honda did. The Pioneer 500. It takes me back to the 90's when the fourtrax 300 and Kawasaki Bayou ruled the trails. Back when bombproof was such a thing. Back when 2.5" of suspension travel and 24" tires were all you got, but you made it work. As we all have, I've seen 2WD Fourtrax 300's do things they shouldn't have been able to do and still ride home. This was when Brand recognition was built on quality. Today's consumer wants it all and wants it now. They will deal with the repairs later. "Look what I got" is greater than "look how long I've owned this." It is partly why I purchased my RZR 570. This most recent purchase, however, was made based on history. The Polaris' are eye candy for sure, but I wanted bombproof. I wanted a brand built on proven reliability, not spec-sheet performance. I did my research, took my time, and made a confident purchase. I didn't jump right in to satisfy my want with the Article Cat Wildcat trail. I waited patiently with due diligence, and made the right decision. I am confident years down the line when I reach for that key on a cold December morning to climb the gap in pursuit of my trophy, it will be a Honda key. The same one I have now. I bought this unit with patience based on history. I set the spec sheet aside and didn't rush. I did it the Honda way. For that, I am thankful.