There is nothing as good and well maintained like in the DS era.
What you have today is only two options regarding flashcards: Gateway 3DS and Sky3DS.

Gateway 3DS would allow you to play games of any region as it overrides region lock, it would also let you use homebrew (that is not so prominent as in the DS era) and would you let do all kinds of hacks, as well as install eShop software and even normal games in the 3DS home menu.
But Gateway 3DS only works with 3DS systems that have firmware version 9.2 or below, and also requires some previous steps to work (eg. accessing a specific web page in the browser).
Sky3DS would only let you play in region games, no imports, no homebrew,  no eShop games. But it works in any firmware version up to date and doesn't require previous steps to work.

Also you have to take some precautions if you play online.

PS: What is your question regarding the 3DS XL?

This post has been edited by sarkwalvein, Fri, March 20th, 2015 at 20:37