I use it all the time. Was a little weird to get used to at first but I can now hold my 3DS in the perfect position everytime without even thinking about it. I rarely turn it off usually only when other people want to watch what I'm doing.
Games don't look as good without it in my opinion now that I'm so used to it.
I don't like having it on, but on my old 3DS, the switch isn't working right, forcing me to almost always see everything in 3D... ;-; On my new 3DS, I always have the 3D off.
Tend to avoid it because it makes me go cross-eyed/gives me a headache but sometimes it's kinda neat to see the depth for a few seconds before it gets too bad.
I like to play in 3D mode as it makes everything look better, more detailed and aesthetically appealing to me. My partner and two of my sisters can't see in 3D at all, ever, so I never have 3D on when others are around unless asked to demo it. Nor is 3D allowed on around children. I do allow my four year old nephew to play AC with me, and will let visiting kiddos try it out if they like, too. But under no circumstances is any level of 3D allowed. Those warnings are no joke and I wouldn't allow any child younger than 12 or so (especially with a family history of vision problems) to see 3D on a handheld device, and only extremely carefully on a big screen, either.
But when I'm alone - I love it! Everything is so much brighter.
I can only use it for short periods. It doesn't really add anything to most games imo so I don't really care. It's quite useful in some of the levels in Super Mario 3D Land though but other than that I don't ever use it.
No, honestly! I want to love it and use it, and although it doesn't give me any sick feelings or whatnot, it's just the effort of positioning your ds in a place where you can comfortably see the 3d display, and keep it that way!
No, it's super lackluster. Not to mention you have to hold your system/head a certain way to even be able to clearly see your game. On occasion I'll use it while playing Pokemon during an important battle, like the champion or the last battle with Serena etc.