My boy has an 170 rzr its being good put the big wheels and faster sprockets on it there a bitch to start once in awhile and I put $1500 dollars in repairs in it Athabsca polaris dealer is garage with there warranty other then that I WOULDN'T every buy one again my boy is 9 and I should of bought him a rzr 500 With every thing it was like $5800 bucks
My brother bought Pitster 150? for his kids a few years ago. He upgraded the shocks and did a gearing change and it still is running. Its gone thru hell and back as far kids can run it and he is still very happy with it. 1/2 price of the Polaris 170. He said if you do some searches on the web you can find some good tips/tricks on modding them a little and to make them a more trail friendly machine vs just a yard machine.