It's weird though, why couldn't Galaxy just download the 100MB patch file, and then apply the patch in the background, instead of downloading the entire thing?
GOG needs to do a major rethink on how to do this more elegantly.
Definitely - from what I gather Steam manages to (most of the time) handle patching better than Galaxy.
It doesn't make sense that a platform specifically designed to facilitate automated patching (among other things) does it much more inefficiently (in terms of bandwidth) than grabbing the individual patch installers.
And it's also strange that the manual downloads and the Galaxy downloads appear to not reuse each other's resources - I get they're almost certainly being built by different teams, but surely they can communicate once in a while and get on the same page once in a while?