2DS has a small screen, the buttons feel tacky, it only has one speaker, and it's annoyingly bulky so wont fit in your pocket easily.
Go for a 3DS XL, I upgraded from a 3DS a while ago and it was so worth it. The buttons have a nice feel, the casing doesn't creak when holding it like the old model, its more difficult to get carpal tunnel from the 3DS XL because it's bigger, it has better battery life... the list goes on. xD