I have both and wouldn’t get rid of either one.
They are both unique and great pins.
There is a good support thread here on Pinside to help with issues.
The newer built Alien pins haven’t had many issues. I’ve never had any problems with mine.

I would keep Tron LE and contact Wayne in Australia to see if he has any left.

How can you see if the game is a later production? What are the production dates?
What are the problems with the first ones?

Not sure about the rules in comparison to eachother but as far as sound quality is concerned Alien is better. Lightshow, hard to say for me.

Same here.

I've had both and while Tron was one of the nicest looking pins I've had, I'd rather PLAY Alien over Tron. Alien has way more shots and combos, better sound (assuming both are stock/no subwoofers or pinsound added) and the modes are more fun. I wouldn't trade my Alien with fixable issues for my modded out Tron pro that I no longer have.

I have both as well and both are at the top of my list of favorites. I would highly recommend picking up an Alien though while prices are “cheap”.

A working alien is one of the best machines out there period. Problem is how long until something doesn't work. For some not yet for many too often. Thankfully some people are sourcing out parts which would make me sleep a little easier at night as an owner but still.... Reality is the game is a gamble but even I have been thinking about it again more. Such an amazing game.....

Alien has excellent sound and a really good code. The only issue I have is it has a very dark playfield.
The rules, shots and play are incredible. The shots flow really nice. Having the capability to choose Alien or Aliens movies adds another dimension to the play.
To my knowledge all LE were made in 2018 towards the end of production of the company.

The only thing I’m going to add is lighting. Otherwise in my opinion, it’s an incredible pin that I’m not letting go of for a long time.

Later production games were made in the fall of 2017 and 2018 until the company closed.
The first production pins had Zeno issues and IO board problems. Personally I’d stay away from the early additions and try and get one of the later production ones.
I believe there are fewer than 200 total Aliens made, no confirmation on the exact number.