I know nothing about pellet grills. However the major deciding factor in anything I buy new is that it is "Made in USA".
If your buying used private sale it's not as critical in my mind. So if they're both American made, I'd take the one with the longer warranty.
Primo XL Oval, Pit Barrel Cooker, Tiernan SOB Custom 24, New Braunfels Black Diamond, Big Green Egg Mini, SJS WSM Mini, Lodge Hibachi, Weber Jumbo Joe
"They'll never forget you 'til somebody new comes along". Eagles-New Kid In Town