Do you mean in the eShop or whatever? Because I'm pretty sure HHD can be played on a regular 3DS, you just need the reader, and that's only if you want to use the cards.
My purple 3DS is unfortunately having some problems on the bottom screen, so it is looking like I will have to upgrade. I'm having a tough time deciding whether to upgrade to a regular XL or if I should just go all out and get a New 3DS XL.
I'm having a similar issue. I have the original 3DS in all its glory (back when it cost 200- something USD). I've cared for it well in my opinion, but I want the faster processor and better 3D. Problem is that I'm not sure which one to get. People say that the bigger screens on the N3DSXL are awesome and you can never go back to the smaller screens. But the system is smaller and I have small thin hands, so I'm not sure if it is the correct choice. Then there is the N3Ds, but it doesn't have bigger screens plus they don't have a black N3DS in the states yet. First-world problems right here folks ;-;
I have the black New 3DS XL. I love the bigger screens and the fact that I'm prepared for future games which will only work on the new systems. I don't like that there's no cover plates option for the XL models though; I'd really love to have the Splatoon plates.
I have a white N3DS since launch and since then, I've purchased the Mario, Triforce, Majora's Mask, Monado and Splatoon faceplates. I got the HHD N3DSXL at launch. Both consoles have a different NNID.