Every time I get a new game I play with the 3D on. 3D was one of the bigger sellers for me for getting the 3DS. I wish I had a New 3DS to see how much more it improved, but alas at this time I cannot get one. However for games I beat already, I usually do a second play through in 2D , just to save some battery. I always play with 3D when I play the Star Fox remake, that's still my favorite use of 3D.