My P520 is only 5 months old but I'll offer my short term impression. As I mentioned doing I did add a Tusk 1/2 shield and 26" wheels and tires. The abrupt shifting when new smoothed out dramatically over the first 30-40 miles to the point that it's not objectionable at all now. The only thing I've done is the first oil and filter change. I will say changing the filter is more involved than either of my Mules or previous Polaris. As I recall the seat and seat back along with a couple plastic panels secured with a dozen or more push pins, along with the airbox snorkel have to be removed just to be able to get to it. Way too much, come on Honda! Fortunately it doesn't have to be changed real often. I think I should find a source and order a couple dozen puch pins to have on hand though.
Compared to the little Mule 610 (now named Mule SX) the P520 is superior in most ways, it's far faster and more powerful and rides better. The little Mule has around 14hp and while it
can get to 22 mph or so on level or down hill, it may drop to 10mph up a grade. The P520 seems geared pretty low and be governed to 37mph but will get there pretty quickly and can do so up grade w/o losing much speed. The 2" taller 26" tires seem to be a win win, they help both the ride and gearing. Its small size makes it a breeze to ride on my wooded trails and the bed makes it more useful than an ATV. There's a chain saw and loppers in mine practically all the time. It comfortably fits two large adults, or 1 adult and two smaller people such as myself and two grandsons 6 and 8, but there's only belts for two people. I like the throaty sound of the single cylinder Honda engine. I find it to be a fun little SxS that's fast enough and functional.
However compared to a larger SxS such as the Polaris midsize Ranger 500 or my Mule Pro MX the little Pioneer rides choppy, or maybe I should say the larger machines ride smoother allowing them to go faster over rough ground. The infinitely variable CVT shifts seamlessly where the Pioneer lurches a bit shifting up and down between the 5 gears. But it's nice being able to short shift the pioneer up in to a higher gear to lower RPM when say on level and not needing the power. Neither the little Mule nor the Pioneer have power steering and it's really not
required IMO, but my Mule MX's PS does make slow speed turning effortless.