Is there any limitation in the GOG version VS. Steam?; Here is cheaper :)

Thx in Adv.

Looks like not. GOG Galaxy build is equal.
There is no multiplayer by Internet in GOG (offline) build. You need Galaxy build/verification installation by client and logged in by GOG account.
But this still more than Steam.

GOG version superior for original game. It is still complete version with all oficcial editions and working OGG music. ANd it is available entirely separate as origonal should be. Two normal offline setups for two differ Quake entries. Plus one for RTX.
Old HTML documentatiln is missing in Steam version of Q1/Q2. Bethesda did exactly update original Steam version and bring back old version as some kinda "steam-o-backported" files. 100% same original content... Except readme/manual in doc+html. Not 100% accurate.
And you need install both as one installation. Same as for RTX. So to get all 3 you need all 3 installed. While in GOG you need it for RTX only make it two installations maximum.
For Enhanced in GOG you no need install original game like in Steam.

I have the remaster on GOG and it is nice. It has even official gyro aim support for the PS5 DualSense controller. (unfortunately no gyro aim for the Nintendo Switch Pro controller)

I think the only thing the GOG version misses is, if you want to use in multiplayer the chat with a controller. There will be no keyboard layout like on Steam, where you could use the chat with your controller. So If you use anyway keyboard and mouse I think there should be nothing to miss.