The plotline was a little corny, but the action was sollid, it developed well without dragging and it was visually pretty amazing. I think you will miss some of it not seeing it in 3d. Really the best 3d movie I have seen.
I wouldn't say it was corny, I would say it was old, washed up, and boring!
The colors, effects, and action scenes were good though.
For me, the 3D didn't add anything to it.