I got the original 3DS when it first came out, and I recently upgraded it to the New 3DS XL, in black. I have not regretted this one bit. The 3D feature is now awesome instead of nausea-inducing, and the screen is so much bigger. I love it and I bring it everywhere (though this might be because I am severely addicted to Streetpassing).
I have the Zelda 25th anniversary edition, which I love (got it secondhand). I don't use the 3D so I don't care that it's crappy and I don't really care about 3D anyway so I don't miss it
It depends on you. The screens are bigger, the processor is faster, the battery lasts longer, and the 3D actually works and doesn't hurt your eyes. (At least it doesn't hurt mine). I was willing to upgrade my pink 3DS XL because I would only have to pay $100 with GameStop's trade in program. If the features of the new XL sound good to you then I say go for it, or if you're unsure you can always go to a store that has a demo unit you can hold and stuff to see if it's something you want.