There still actually hasn't come a moment where I have actually NEEDED the 3D. I have tried using it for a few small things, but the images keep flickering and dancing to the left and right. Besides, what am I actually losing with the 3D off? I'm not losing anything as far as gameplay goes, really...
...and as far as my eyes adjusting? Even if I turn the 3D on just a little bit, I have to recoil in pain because of the immense eye strain.