>>713950261They're also backlit so you aren't relying on the sun to tell what you're even doing, nor are you having to buy batteries for both the cartridge and the handheld, the only other platforms Crystal can run on that are backlit and don't have the filter are the N64 with a Transfer Pak and Stadium 2 or a GBA SP, even then each version misses out on something the others have.
Playing Crystal on the N64 gets you direct connectivity between Stadium 2 and Crystal, but it's no longer portable and you don't get the Odd Egg or Celebi events.
Playing Crystal on a GBA SP is the only way Crystal can be backlit and unfiltered while still being portable, but no events and since it's not Stadium 2 you don't get to speed up the game.
Playing Crystal on a 3DS makes the game backlit and portable, it gets you the Odd Egg and Celebi events and there is no battery to run dry like there is for the original cartridge, but it has a dark filter and it can't connect to Stadium 2.
Pick your poison, none of them do everything every other version can all at once, so you may as well play the one you dislike the least, there is no such thing as the definitive gen 2 experience, which sucks, but there's also nothing that can be done about it.