It's too late to discuss the game itself - the game is a marvel. But it seems like developers don't like gog, as a result you will get an outdated game! If you are about to play the game as it is - fine, but if you would like to use mods, and there are good mods, you are in trouble. New version of the game, which is available only at steam uses new format of loc files, which many mods are using as well. So you wont be able to play gog version with a new mods - whats a shame!