Alpha Centauri was one of my favorites back in the day, but I don't know how well it has aged.
Is it worth picking up if, as in my case, it does not have nostalgic value?
I strongly suspect that any civ fan, as well as most gamers who haven't yet played a civ game, will have serious difficulty escaping the vice like grip of any of the civ games
or indeed of alpha centauri.
For what it's worth, apart from briefly checking out the demo when it came out, my first real attempt at alpha centauri was only a couple of years ago, and I massively enjoyed it. It has its own totally unique vibe going (reminds me a little of star trek universe come to think of it). The only thing that will stand in the way of a new player is the interface. It's not that it's bad. It's just really unusual and takes a little time to get used to.