I actually forgot the all the armors from the trailers. Even so, trailers aren't a viable means of setting up a plot point. It needs to be set up in the film, and this was weakly set up for me.
Like I said, I felt it was set up enough in the film. We'll just have to agree to disagree on that.
Another thing that was poorly set-up and ultimately made the film ring emotionally flat for me. It was a real shame because I love a lot of Shane Black's work.
Regardless, the point in bring up the armors was in comparison to the extent in which the Phantom drive could be considered a deus ex machina (to bring it all back to MOS and this mind vs muscle discussion).
I don't think either of them were deus ex machinas. I don't think the Phantom Drive was a brilliant plot device but I didn't find it to be a deus ex machina either. If anything, it seemed like the most predictable thing ever to me even prior to any of the trailers we got. How do you get rid of General Zod and his army without killing them? Throwing them in the Phantom Zone somehow.
However, I don't think it's fair to say everything Tony did in IM3 was on par with the Phantom Drive. Tony himself created every weapon and armor he used against Killian. He saved the day essentially by being a genius throughout the whole film, even with incomplete armors. On the other hand, the Phantom Drive was just Superman/Lois/US army following the instructions of a hologram Jor-El on what to do. They didn't come up with the idea themselves.