Honestly, I really didn't enjoy Afterlight as much as Aftershock, my main beef with it being that it just gets so grindy and tedious after the Beastmen show up (which is to say, about an hour or two into the game).
Most of it stems from the fact that instead of things being built on their own, everything requires that you assign people to it. While it may not be a big deal for things like research and base production, it makes expanding and upgrading your turf long, boring, and irritating since you have to send people out and watch as they slowly drive over to a sector, claim it, and then have them go and build stuff on it. Which, if it borders enemy territory, has like a 50% chance of automatically triggering an attack which you have to repel or else the territory is lost.
It also doesn't help that they changed the resource system: instead of having an income of three different resources, you "level up" about five or six different ones by building mines on sectors with the corresponding resource. While it's great that you essentially have unlimited resources, it becomes a huge grind to get more as you slowly carve into Beastman territory, hoping that the next one you conquer will have metal or crystals (since a lot of them don't have anything at all), build a mine on it and possibly have to defend it as yet ANOTHER attack gets triggered, rinse and repeat ad nauseum.
The resource problem wouldn't be so bad if their placement were actually randomized, but it's static each time. Also, with the way they're placed, you can very well end up researching something cool but not get the actual materials to make it for upwards of two or more hours. It sucks.
So yeah, if you really, really want to see how the Afterblank trilogy ended, get it. If you're expecting something as streamlined as Aftershock, you're probably going to be disappointed.