Quoted from Budman:
I haven’t been able to find a Premium but have a line on a low play Pro. Why do you prefer the Premium?
Not everyone agrees that the premium is better. But, this is one pin where I where I think the Premium/LE shines.
I think the magna slings are awesome and fits the theme perfectly. Some people think they are too random and like the traditional slings on the Pro.
Ramps and subways are another difference. Also moving Slimmer. It's not s huge deal per se, but I like that it's kind of "hidden" and then comes into the action when needed.
There are a few other goodies: steel ramps, ecto goggles, better plastic models (library and storage facility).
Different artwork. Depends what you like. I don't pay much attention to the cabinet art work and the playfield artwork is the same, so.. meh.
For what you get and the price difference, I think it is totally worth it. YMMV.