Depending on what you are looking for in a spa? Difference wise looks, filtration, jetting, and size. The cabinet on the JLX is gorgeous, be a shame to sink it in a deck all the way, if it were say 50% exposed would look fantastic. Over all a nice spa for 4 people if you need more room then the J-470 or possibly the J-465 Which 400 mdl are you thinking about or comparing to?