I'm thinking of getting the game and recommending that my friends to get it as well. I use GOG (obviously), they use Steam.

Per this thread (https://embed.gog.com/forum/sins_of_a_solar_empire_rebellion/network_error) there was no out-of-the-box crossplay, but there was a work around.

What's the current state of crossplay?

*Does the workaround still work?
*Did they fix the issues so that crossplay is available without the workaround?
*Did they "fix" the issue to screw consumers by blocking crossplay?

I have no idea. They have updated the game, but not yet put the Last DLC in the game here, so they will lose out on content. Other than that, the game is playable with (lan) without using Gog Galaxy. Sorry, I don't use galaxy.

Since none of you have the game yet, is there a reason your friends cannot buy this one game from GOG instead of Steam? That would ensure you all have the same version and get updates at the same time.

What DLC does the GOG version not have...?
They're all present.

The "Minor Factions" DLC does not seem to be available on GOG. Whereaminow25 is quite sore on this point and will bring it up at every opportunity. While this DLC would be nice to have available, the game runs fine without it. You just cannot use the features that were added by that DLC.

That is like ordering a sandwich and find out that the Bun is sold at a different store. How are you supposed to enjoy your sandwich without the bun?

I think a more apt example would be ordering a burger at the local McD but finding out adding cheese, one needs to get to another McD franchise. Many people can enjoy a burger w/o cheese but I do understand the frustration of not having the final DLC here. I to would prefer to have a full GoG version than break down and buy on steam.

I too would like to get the DLC from GOG. I happened to have bought Rebellion from GOG before Minor Factions was even announced to exist, and I have enjoyed Rebellion on its own. I still come back to it from time to time, and I'm glad that GOG continues to receive patches from the publisher for Rebellion. If Rebellion were banned from GOG over the lack of Minor Factions, as Whereaminow25 seems to want, then those of us who already have Rebellion through GOG would likely cease getting any patches. That seems like a bad deal to me. I paid for it here. I expect that, to the extent the publisher continues to create free patches for the game, then customers who bought it through GOG ought to get those patches, just as customers who bought through other stores do. I won't begrudge the publisher when they inevitably announce that they no longer want to support Rebellion and will not be producing further patches for it, but until that day comes, I want to enjoy the same level of service that is provided to customers who bought the game through other platforms.

I have not bought the DLC through Steam, and have no intention of doing so. I would feel more strongly about its absence here if, as with some games, a post-DLC patch changed the balance of the game such that playing without the DLC is clearly poorly balanced in a thinly veiled attempt to make everyone buy the expansion.