The Deluxe update includes both 40 new puzzles as well as "refined" examples from the 3DS version. You also get all the previous DLC right from the start, and there are 50 new outfits you can earn through gameplay. You may have reasons to buy the Switch version even if you've played through its earlier counterparts, then. If nothing else, this gives you a rare chance to play a Layton game both in your living room and on the road.