If the same game is available and on sale on GOG and Steam, on which platform you rather buy it?
I've had this question looking at the Quake con sale, and Call of Cthulhu Dark Corners of the Earth is for sale on both platforms. I ended up buying it on GOG. What is your opinion?
Check out Heroic Game Launcher. It works with GoG, handles GoG Galaxy Cloud Save support, and works with Proton (similar to Steam). A very good client.
As someone also using Linux, Steam has an official client, the workshop and is continuously advancing gaming on Linux. While GOG promised a native client years ago they haven't delivered and Heroic has much fewer features than Steam.
Yeah, heroic is amazing and I really appreciate the amount of work that's gone into it. It's still much more convenient to buy direct from Steam and it rewards the company for the efforts to push gaming on Linux forward.