I have over a thousand games on Steam and several hundred on GOG, so either is ok. Steam is just a little easier as an environment for me, but all else being equal I have a little bias towards DRM-free so GOG.
I'm just asking, any advice before I click to use GOG?
For example, I see this expansion and in case I want to get it at some point, I see people with GOG asking how and not getting answers.