I have seen Iron Man 3 3D in the Disney El Capitan Theater.
There are some scenes where the 3D is barely noticible, but this is only the minority of the movie and isn't that bad after you see the whole movie. Basically more then the majority of this movie has good 3D, well some of those parts are normal 3D which is still good. But if you want to notice the 3D effect 24/7 then go see it in 3D IMAX or substitute IMAX. I only saw in a regular size theater screen because I had an extra ticket for OZ prequel 3D, so I went to exchange it and luckily they did, so I was it for free instead of paying $6.00¢ to $6.XX¢ for it. But the experience came with better 3D sound, specifically Dolby Atmos (64 speaker sound), and I still love seeing the 3D intro for Dolby Atmos.
I saw it on a bigger then 500 inch screen but NOT IMAX.
The scenes from the 3D trailer have a more better 3D effect in the trailer then they do in the full movie for some reason LOL but it's still good enough luckily. I just don't know why or how this happen with this stereoscopic movie.
I would rate this movie 8.0 out of 10, but I would never give this less then 8.0 and I would never give this more then 8.0.
Its easily better then any of the previous Iron Man movies.
The set up for Tony Stark & Iron Man to become one, in a future movie is done in this, and I like how they mix-match the stories & plots of certain parts of the comic book and give you some real plot twist(s) that you won't see coming until you arrive at the scene as well.
it's simple enough to understand the stories & plots for those of you who complained about Pirates of the Carribean 2 & Men in Black 2 being too hard to follow (I seriously don't understand how anyone could have hard time following any movies storielines). But it's not water-down in quality for doing so, luckily.
The directing is unfortunately the same as the first 2 movies, but it is the same director.
The end of the credits shows a scene that is only in 2D for whatever BS reason when everything else was in 3D for crying out loud. But maybe it's not the same for the 3D IMAX version.
I would definitley recommend seeing Iron Man 3 in 3D IMAX.
Sort of off topic:
I'm glad I saw the Great Gatsby 3D before Iron Man 3 3D, and I was thinking of seeing Star Trek Into Darkness 3D IMAX today but I wanted to see animation domination and see both the Simpsons & family Guy try, LOL.
I think next week I will see Epic 3D XTREME (3D IMAX substitute) and hopefully after that I will have time to see Star Trek Into Darkness 3D IMAX substitute on the same day, since I am going to see a 3D Movie again next week, I figure I would go see Epic before Star Trek 2 since Epic will be out by then and I like to scale up in seeing a movie in quality, and I assume Star Trek Into Darkness will be better, but Epic does still looks like it will be a really good quality movie, plus it was originally titled "Leafmen".