Yo can play the same games in 3DS and 3DS XL. But I recommend to you, to buy, the XL model, because it has best battery duration and the fingers can't be market.
The XL has more possibilities to be actuallity, than the normal 3DS (the normal 3DS will discontinued more early than XL) The sound is better.
The only imperfects are:
The screens are 90% bigger than the original model
The Nintendo DS games has more pixels and it losses resolution.
This is my reasons to buy the Nintendo 3DS XL.
Sorry if my english is too bad, i speak spanish.