I love the typical M&B gameplay and openness, much more if we add the infinite modding possibilities for this series, but there are some reasons to criticize vanilla Bannerlord and even more, sadly, GOG or any other alternative non-Steam version. I moved almost entirely to gaming through GOG as main platform, but this is an incomplete, inferior version of Bannerlord. Firstly, focusing on vanilla experience, Bannerlord is a mediocre M&B at best, even more considering its long development. Action combat was minimally improved and obviously the change was even bigger graphically, but on the other hand Bannerlord was simplified in all other contexts with worse rpg mechanics and social interactions in general than Warband: Minimal individual npc personality and relations, clans replacing individual lords as main social focus, far less dialogue options, less diverse quests, even more generic companions than older games, no feasts, worse implementation of skill system, no camping and resting outside (and consequently also lacking related surprise attacks) etc. The game gameplay feels less diverse, less unique than older games which says a lot considering how basic were older games in those contexts. If that's enough to grant a 3/5 score to the game despite still being a "fun enough" game in vanilla, GOG-Bannerlord or any non-steam version are even worse in regard modding: Players have only access to a single updated version of the game, breaking hundreds of old mods and what is even worse there is not support for official modding creation tools outside Steam (+ lack of support for alternative unofficial tools mostly working on older versions of the game). I asked for a refund the game and I lost a lot of respect for TaleWorlds.
This thing isn't compatible with thousands of mods because it's not true normal Skyrim Special Edition (1.5.97) but a new updated edition exclusive for GOG (version 1.6.659). If in the future GOG offer a downgrade patch or maybe Bethesda (lol, sure) or if modders add enough support for this new 354th version of Skyrim, I could consider to purchase this, meanwhile this is one of the few cases in which I can't recommend the GOG version, because mods are the main reason to purchase Skyrim. If you don't care about mods, then GOG version is the best option, as usual. DRM free, offline gaming possibility, ownership, etc. However Skyrim without mods is a mediocre game, just the third/fourth best Elder Scrolls title, good enough for true fans of the series, but just 3/5 at max for general players.