I'll give it to you straight. I'm a Nintendo fan but, at some point, I just didn't give a fuck about my DS anymore. I pretty much quit buying games for it unless it was for my kid. Keep in mind that, since launch (and I bought a DS on day one), I purchased and still own SIX DS systems. I got a PSP and I never looked back.
I got a 3DS last year and it blows my mind how much Nintendo got it right. I play it when I'm home. I play it when I'm at work. I play it alone. I play it in public. Yeah, I got a Vita, too. People don't like to admit this but it's pretty awesome (with lots of PSP titles ready to be played).
I say you should get both (though I'm worried about the Vita's future) but I will honestly say that it is a joy to own the 3DS. When it comes to games, it's just awesome.
