Larian Studios Forums Divinity - Original Sin Divinity - Original Sin - Enhanced Edition DOS EE - Get Steam or GoG version?

Firstly it depends on your opinion of DRM, as Steam requires you to have a Steam Account and Steam client on your PC, whereas GoG's Galaxy client is optional, and you can download the game without needing a third party client.

I have not used GoG Galaxy properly, so I cannot comment on the quality of it's automatic patching service, but Steam's Automatic patching is very reliable (from my experience) and if you opt not to use the GOG Galaxy client, then you will have to keep track, download and apply your own patches.

Check http://larian.com/forums/ubbthreads.php?ubb=showflat&Number=504042 for discussions regarding the original D:OS.