>>13820130Launch 3DSs have an issue where the gap between the top and bottom halves is too little so the circle pad and the border on the bottom screen touch the top screen, leaving (removable) marks.
XL's resolution is the same as the normal 3DS, but the screen is bigger so it just looks more pixelated.
All of them lack a second circle pad so stylus games can be awkward if you're left-handed unless you buy a circle pad pro accessory which is just a bandage on a design flaw.