Why? I played the steamjversion of a friend 15 hours+ and the only bug I had was that the competition at archery where the guys do not shot any bolts..... No crashes.....nothing.

6 GB left... I'll probably play the game in an hour. Hope for no bugs and fine modding!

Changes in save game system (save on exit), lockpick mini game, the list is quite long.

I do not need any changes on save game. I think it is to easy if I can save at anytime. And lockpick mini game get only changes withe gamepad, I play with a gamepad too, but use mouse+keyboad for this. I do not believe it will become much easier after a patch.
This are 2 things but you said the list is long......I say everybody can play the game at the moment without any crashes or storybug. The game works fine for me.... It is my own opinion....If anybody want to play the game.....play....and do not wait because anybody told it is very buggy.

Is it downloading super slow for anyone else? I went on steam and my download speeds seem to be fine there, but on gog galaxy it's downloading at .4 MB/s I don't understand. I usually download games on steam at 8 MB/s and I recently downloaded divinity original sin 2 like two weeks ago fine. I don't know why it's so slow right now. Is it because the server are overloaded? I'm just wondering if it's downloading faster for everyone else.

For what it's worth, downloading from the US through GOG Downloader gave me the expected 5Mbps.

Not sure if Galaxy uses different servers or routing, but my download was quick and painless.