I've got my poptart ACNL 3DS XL. And then another copy on my old Black 3DS. Been playing on the Black one more often recently while on holiday so as not to risk poptart, and so I can carry it round to wifi spots easier.
I'm currently playing it on a Red 3DS, but I'm getting the Blue 3DS XL for X/Y soon and will be transferring my data to that, and probably end up getting a second copy of New Leaf eventually to play on my red one to cycle villagers out to people