The JD decks will stripe actually, it's an optional add-on kit.
Look on simplicity's website, it's their latest selling gimmick, "automotive style suspension"
I would hope it hasn't given you any trouble at 175 hours, because that's nothing.
In short, no, I didn't look at simplicity. I find them extremely ugly, and cheap. It looks like a cheaply made small import vehicle. As coobie pointed out, your mower deck is a thin 12 gauge steel. John Deere uses 7 and 9 gauge. Simplicity has a 3 year warranty on the Legacy XL, John Deere has 4 years on the X700 series. John Deere offers a diesel engine in 2WD, simplicity does not. John Deere uses a vastly superior Yanmar diesel engine in it's diesel X7 units. Simplicity uses a briggs & stratton diesel in it's Legacy XL. There is no comparison between the 2 engines, the Yanmar takes the cake.