Here is my rule of thumb; if the movie was shot in 3D, with 3D cameras, then I might see it in 3D. If the movie was shot in 2D and converted to 3D during post-production then I'll watch in 2D.
STID was converted to 3D during post so, I'm sticking with 2D.
I'm still not a huge fan of 3D, I think it is more of a gimmick then anything and it never really adds anything to the enjoyment of the story IMO, just eye candy. I also don't like how the glasses make the movie appear darker. I also hate that it cost $3 more at my local theater, which is why I always keep my glasses when I do see a 3D movie just because I can. I know that keeping the glasses doesn't really do anything but I pretend I'm sticking it to the theater for charging me more.