Me and 3 friends have had a lot of fun with Divinity Original Sin 2 multiplayer. There's usually a lot of shenanigans and fun happenings as a direct effect of having several players bringing their own style to the game.

Just be advised that the experience will not be the same as playing single player. From what I understand the multiplayer experience in BG3 is much improved but I found that when playing with friends in DOS2 that I could not for instance take the time to dive in deep with conversations, quests, lore etc as I would like.

There is also a current issue in that if someone joins your game with a custom character, that character will from then on be a permanent member of the party. You cannot at the moment get rid of them in any way.

Bottom line it is fun, but you should treat it as a separate thing from single player - and definately have a dedicated playthrough for multiplayer.