It appears as though the Steam community for GC3 is really active. Lots of multiplayer, lots of uploaded content, etc.

As Steam and GOG servers don't share data, I am wondering what the state of GC3 is here on my preferred platform?

Are there ample multiplayer matches, custom races, and the like? Or should I look at Steam to scratch this itch?

Thanks!

Of course here. Why would you give any money or rewards whatsoever to the consumer-hating entity known as Valve?

Because a major portion of this game is multiplayer. And the dev didn't implement IP-based hosting. So, few people play multiplayer on GOG, then I am far less interested.

For first person games, I always prefer GOG.

But multiplayer? Well, you can't get EU4 or CK2 on GOG. GalCiv3? Dependent upon servers and, from what I have read, this game cannot make use of Galaxy's ability to connect to steam players. Sure, they intend on changing that, but the timeframe is unknown, so I can't make a decision based on a non-binding hint of a promise by a dev.