I really doubted whether the 2DS was a good purchase at the time (Christmas 2013) but it has had as much usage as the 3DS. I guess the kids aren't really that interested in sound quality and the 3D feature anyway - they're just interested in playing the game. There's no squabbles about who has which device when they're playing multiplayer.
Can't comment on the new 3DS as we don't have one... 







