I have the Hori Duraflex case for my MM New 3DS XL.
The only complaint I've heard (and noticed myself) is that it's a little loose. Not like it'll fall off or anything, it's just easy to slide off and it would be nice if it was a little tighter fitting. But the older version may not have that problem. And it's honestly very minor anyways. It is pretty thick, but you can see the design through it, it's not too cloudy. I was worried about that too, but when I went to grab a screen protector at EB Games, the guy working actually showed me his (beautiful Monster Hunter) system with the case on it, and it looked fine so I grabbed one.
Mostly because my old 3DS had a bit of wear on the sides from my hands rubbing it, which I wanted to avoid with this one. Hard to say since my system is darkish and not white, but I think it should look fine.
On the other hand, you could always just get a carrying case with a plush interior to keep it nice. But if you're specifically looking for something that covers it while you're playing, the TPU cases are really one of the only options I can think of.
Except, for full-body clear skins like this;
http://www.skinomi.com/sk11415-nintendo-3ds-xl-skin-protector.html
The only problem I can foresee with that is the same with screen protectors. Tiny dust/hairs might get in there during installation, and in this case installation is a bit more tricky than with a screen protector. You actually use a liquid to apply it (which I would worry about getting into ports and such, tbh), and since it covers the entire system, getting it just right may take a bit of finesse. If you decide to go this route, they are removable, although apparently a little tough as you need to apply low heat to remove. Once applied though, they do look pretty tough, and you would get the clear finish you're looking for without the bulk, so might be worth looking into. c:
