Although most of the people that I spoke to about
The Great Gatsby said it was very slow, they did say that it was visually stunning (which is why I'll watch it OnDemand at some point).
The effects supervisor on the film recently released this reel that shows the dramatic difference between shots before and after the visual effects were added.
It's really amazing what they can do these days, as you'll see (
enlarge the video screen for the full effect)....
I also love the music they chose for that video. Very cool.