Well there are some unique features for the top of the line LX. Instead of a separate sear burner all of the burners have high+sear. The lid is a bit taller only on LX model. The SS is higher quality. The knobs are back lit. The ignition system is an infinity ignition system built in separate for each burner. The left side table folds down. I don't think I'm forgetting anything but I might be. They work very well for me. That said I can sear a perfect Steak on pretty much any Weber.