Buy a 100 series because you're on a Craftsman budget and you want green & yellow w/ the JD name. Buy an X300 because you want a lawn tractor of the quality that has traditionally been associated with John Deere since before they began selling in Home Depot & Lowes. Either way, buy it from a JD dealer since they're the same price as Lowes on a 100 series (and can/will probably match any 10% off incentive that Lowes offers, if it's in writing--though I don't know this for a fact), and the dealer will be the one servicing it either way so you may as well begin the relationship as early as possible.