I have not played Avengers Pro. I like Tron Pro more than the LE. I found the ramp lights distracting and excessive on the LE. The light show on the Pro is awesome enough without lit ramps. The Pro version I owned had LED lights added, lighted recognizer, upgraded plastics making it very close to the LE but obviously not the same.
Having said that, I think Avengers LE is twice the game as a Tron Pro. On Tron, I love the light show and it has awesome music. The game play itself? Slightly above average.
Avengers LE, I love the lights, I love the music, the call outs are hugely better and I have never seen a layout anywhere similar to it. The game play is quite original.
Both games are rather fast with the edge slightly going to Tron. I found the Avengers table more entertaining though with better variety of shot selection. Plus, HULK makes this game for me. He is well integrated and rather amusing.
Avengers Pro is missing a few features that probably cannot be aftermarket upgraded so I don't know how it would compare in game play.
I realize that comparing AVLE with Tron Pro is not answering your question directly, I am only trying to relate my similar experience having played both Trons and AVLE.
These are, of course, MY opinions. Others may disagree and I will agree that they are wrong.