I played a 3DS today!!
It was pretty cool! I didn't feel sick and my eyes didn't hurt at all! I had the 3D up to full, and I just held it the same as I hold my DSlite and the 3D effect was totally focused the whole time, if you tilt it, yeah it will go out of focus, but it's pretty easy to keep it focused!!
I was playing a 3D camera game where targets and monsters would appear in 3D, from a "?" card the guy put on the table irl, and I was moving the 3DS around to look inside of this 3D box that looked like it really was there and moved in relation to me.
There was even a target inside the box that I shot and I had to move the 3DS to get to it, cool fun!!
I'm going to get one for sure! (I always was, probably, haha) but I'm positive now.
The 3D is very clear and sharp, I think the screen is as bright & crisp as a PSP's, I might get Nintendogs & Cats or Street Fighter 4, both would be cool!
Also it's very light! I had my DSlite with me for the Pokemon event and I noticed no different in weight or unit size.