This stump grinder debate is about as fruitless as which saw should i buy.... Husky so n so, NO Stihl so n so, but i like my Echo so n so... flame flame... To the OP it sounds like it has a bit hi hours for the price they are asking for, if they have maintenence records showing it has been well maintained and has new tires fluids and extra teeth and a spare tire for the trailer or two then give them an offer a little lower then their asking price it may be worth it. What are your immediate needs compaired to future needs? The rental companies around here only use the sc252 which leads me to believe that they are fair priced new, tuff as nails (idiots use them everyday and they still function) and parts have to be fairly cheap and easy to come by (again idiots and all). I own a vermeer 6"chipper and most of the reviews here i read about it were its under powered slow and there are better machines. but really i dont feed it anything more then 5" most of the time because we buck the rest for fire wood. and from what i have read NO one likes a stump humper, but the majority of my work has been "hard to access" trees that maybe a self propelled grinder would get to, so a humper is whats in my future (their cheap too). I have watched a few carlton grinders operate and i have used a sc252 I wouldnt call either of them "fast" and im not sure i understand what you guys are talking about when you mean production? Do you mean like working for the city, and doing 5-10+ trees a day? if that were the case wouldnt you want a tow behind with massive amounts of power that you could position with the truck? that would seem faster then slow walking a self propelled grinder to where it needs to go.