Quoted from Aurich:
The difference between Alien and TBL is there are some 100-200 Aliens out in the wild, as opposed to the handful of TBLs, so there's simply more scale to the resources.
Alien also has a team of people still around able to offer little bits of assistance where possible. It's probably much more finished code wise too for that matter, but I honestly have no idea what the state of TBL code really is anymore.
Still, it's proof that a lot of things are possible where there's desire and a will to solve problems.
Assuming they sell through these TBLs, there will be 80 or 90 out there, bringing it closer to Alien numbers in terms of a self-supporting community of owners.
I don't know what the state of Alien code is, but from playing TBL a couple of dozen times at TPF, the code felt pretty complete to me. Of course there's no comparison to Alien where the coder is actively engaging with the owners on Pinside. But if I were a buyer I'd be more worried about hardware failures than about the code.