Just wondering if the the gog version is the same as the steam? It's half the price on gog so it has me concerned its missing certain features?

They're the same base price here -- though the Steam version's on sale right now and the GOG version's not.

No idea if the GOG version is behind the Steam one in updates, or by how much; I doubt it. Looking on Steam, it seems the devs have been making a lot of official mods (which seems a bit of a waste of their time, but whatever) for the Workshop, which the game apparently supports. Also, I don't know if multiplayer on GOG is Galaxy-based -- I think you have to do it the "hard" way, whereas on Steam, I'm pretty sure you can just let the Steam client handle everything (though you are still able to cross-play with other stores' builds, assuming the versions are the same).

I don't care about online multiplayer or mods, and am okay with waiting up to a few weeks for updates to come to the GOG version (not that I know of this particular game having had that problem, aside from one of the DLC taking months to come here), so I've been happy with the GOG version. If convenient modding via Steam Workshop is important to you, or if you plan to play much multiplayer (especially if you'd be mostly playing with other people who have the game on Steam), then get it there. Otherwise, get it from whatever store you like most that offers a decent price. : )

I own Barony on both Steam and Gog and they're both the same version. Gog updates slower, but still has all the updates. Multiplayer functions the same on both version, too.