The pro/prem/LE differences are many and most were mentioned in this thread. I just don't see the differences adding much to the actual game play/rules of the MET pin. The features on the Prem/LE are more like eye candy to me.
I have played all 3 versions quite a bit, and I do like all of them a lot.
I don't care about the grave marker raising.
I don't care about physical ball locks.
I don't care about the snake's mouth moving.
I think that the color changing LED's are cool, but I can live without them.
I do miss the spinners and I do realize that I can "hard mod" them in on a pro, but I haven't yet.
So, I am not paying thousands more for color changing LEDs and Spinners. The hell with that noise.
The rules to achieving snake multi ball are a little different on the pro. I actually think it's much harder to achieve snake MB on the pro, but I would invite others to weigh in on that fact.