Well I slipped in Final Fantasy III for the DS on my brothers XL the other day just to test it and it definitely doesn't not look as strong on it. I can get a good conditioned 3DS for 80-100 bucks, whereas the XL's are looking to be between 150-200 and I don't know that I can justify that much of a price difference.
Wow, thats funny.... that is the same game I was playing when I made the switch and I honestly didn't notice a degradation in visuals.... and I'm usually a freakin' snob when it comes to that sort of thing.... then again I'll take upscaling over clarity when it comes to a handheld, so maybe my subjective taste took precedence in this case....
In either event, you can't go wrong saving a hundred bucks either... considering the volume of DS titles worth grabbing as well as their availability and price at the moment, that could translate to A LOT of hours of quality gaming.....
I just like big screens is all.... doing art for a living, I'm always looking at small details and my eyes feel stressed... my PSP acts as a home console in fact (video component output= the best thing to ever be built into a handheld IMO...)