I actually tried lameboy on the DSiXl and it looks fantastic.........
The problem I had on the DSL is that being the GB resolution much smaller then the GBA( and even smaller then the DS ), when playing GB games on the DSL basically you get a little square in the center of the screen....
With the XL things are.............much larger, and still , it looks smaller then the original GB ! But definitelu more enjoyable.
Lameboy by the way works great.
Every game that I tried works full speed with sound and moves silky smooth...........and Super Gameboy games also use the extra screen real estate to display the game artwork.
Definitely recommended.
On a side note does anybody know if it possible to import a custom palette, or are we stuck with the gray/green one ?