The SNES styling was what swung it for me, so I got a n3DS over a nXL.
I got an OG 3DS at launch, then upgraded to an XL as soon as they released as I found the original so uncomfortable to use. The n3DS is infinitely more comfortable than the OG 3DS, but the XL's size means the d-pad is is a more usable position and you can use it and the shoulder buttons together without adopting a claw grip. If I didn't already have an XL and just upgraded from the OG 3DS, I would find the n3DS wonderful.
I don't have buyers remorse getting the n3DS over the nXL, but I think I should have got the bigger one as I prefer the form factor of the XL. On the plus side, coming from an XL, the pixel density on the smaller n3DS screen is very nice, and very few game need me to use the d-pad as a primary input.
Unless you want the faceplates or are desperate for the SNES buttons, I would recommend the nXL.