Its almost 1:30 AM eastern time so I'm tired. But I have my 3DS and just want to make some quick notes on it.
If you are used to the ds lite/dsi screens then the 3D top screen looks nice and big and beautiful! The analog stick is really small looking compared to online pictures, but it works great, feels perfect. The rest of the buttons all do their job well. The stylus is nice, extendable, metal and sexy.
Now onto the 3D! It works great. Granted I just saw some main menu stuff and played Face Raiders. But the 3D is the real deal, in your face action. And yes it can definitely give you a headache. I have a minor headache right now! But yes the 3D is very nice. The sweet spot depends on the game I've heard, but so far it isn't bad at all. If you lose the sweetspot, you are gaming wrong. People trying to watch someone play will get some blurry scary mess though, if they are out of the sweetspot.
That is all for right now, I picked up Madden, Super Street Fighter, and Ghost Recon Shadow Wars. I'll be playing them after a good night's rest. Probably the augmented reality games also. As I explore more of the system, I'll do a part 2 of this segment and add more that is missing. There is also a "power saving" mode that I'm not sure what it does, and haven't tried yet. Probably dims the lights or something but who knows!