I downloaded the game but the client says that the download/install/update failed at 92%.
Now when I launch the GOG client and try to repair/verify the installation I get: Updating -> Scanning Installed Files -> Update Failed. I get the message - "Cloud sync failed due to heavy load".

The files seem to be all there and I ran the launcher and got to the main menu.

I now hesitate to buy from GOG and prefer Steam!

UPDATE
Tried again this morning and the problem seems to have been fixed. The update seems to have completed1