The Crystal Clear film of Mumbi's a pretty thick, sturdy and scratch-resistant protective film. The film could be attached to the unit and is easily tailored without problems. At the top of the screen is covered by the film of the narrow edge of the display with what ensures greater tolerance when gluing, because it is not only tailored to the active display area. At bottom of the screen it sits very well with proper attachment.
However, the film has a bigger drawback: It reflects relatively strong and takes the 3DS XL as one of its main advantages.
But if you can live with it has a robust and solid screen protection.