I don´t know where to start, and a full answer would take me an hour to write, so here´s the basics:

Core function (buying, storing and downloading games) broken: I can no longer download and install my games, and when I try, it results in a breakdown of my computer (well, the OS at least, not hardware, of course).
So not only does it no longer do what it´s supposed to to do, it also adds damage.

Bonus features damaged: The forum is now hidden - this was the only feature I used and enjoyed.

The looks - looks are largely irrelevant to me, but I had no objections to the appearance of 1.2. And I will never accept to even consideri the looks before the thing is fully functional.
To be fair, I also found this also to be surprisingly well implememented, and I failed to really appraciate it in the smoke of my fury over the rest :-)

Today I tried to download a manual for a game. The download failed four times in a row. I tried downloading random extras for several other games and each and every single one failed.

I checked to see if it was an issue with the GOG servers by downloading from my library through a browser. Each download went extremely fast.

Installing games does work, but is literally about 100 times slower than downloading the offline installer. When I tried installing Afterlife, a 250 MB game, it took about a minute for the install interface to show up in Galaxy, then about two minutes for the file list to be retrieved, then the game itself started to download at about .5 MB per minute.

In contrast, I was able to download the entire offline installer and install the game in less than three minutes.

To make matters more interesting Galaxy now has detected that I installed Afterlife but it does not launch it correctly. (I can launch it correctly by running the files outside of galaxy.)

Why use it at all indeed?

EDIT: After exiting and reentering Galaxy I was able to download another game (Master of Magic) at the rate of about .8 MB per second as opposed to .5 MB per minute, which is still much slower than direct downloads but at least fast enough to install games in a reasonable time frame. It then installed a 2MB "update" for afterlife, which I am guessing has something to do with enabling cloud saves or something, and now it can launch afterlife correctly.

So it looks like a couple of things are going on: First, sometimes the program breaks and only fixes itself on relaunch. Second, it's most efficient to install via offline installers, but Galaxy does okay after that point.

Honestly the new update to Galaxy seems ahelluva lot more frustrating than before. I've bought a game last night and it still isn't appearing in my list of owned games. Try installing through the website and it opens galaxy to install and it just keeps loading. Why even do this version when it's not properly working?

When games don't show up or the install stalls out I've been able to fix the problem by rebooting Galaxy. Though, as I said in the post above, it's usually more efficient to use offline installers. You can find them on the website at the bottom of the tab for the game (below the big blue button that forces you into Galaxy).

I know that it's frustrating to do things this way and that Galaxy shouldn't screw things up like this, but at least you'll be able to install your games.

I don't know what tagging system you're talking about, the one that I see on the website is identical to the one on GoG 2.0
I'll give you the forums issue, but I've never once had issues with downloads or having the client break my OS, so that might be a problem on your end(maybe try reinstalling it?). I guess it's more broken for some than others, but even back in closed beta it functioned just as well as 1.2 ever did, just with a few missing features and others added on.

After some more testing, I'm finding that after about an hour or two of operation, Galaxy 2.0 refuses to do anything but launch games.

More specifically, at this point it will not update recently played games, it will not recognize newly purchased games, it will not properly download and install games and it will not download extra content at all. It doesn't seem to check for updates and when I try to have it verify/repair, that also hangs and does not complete properly. Play time and other information will not be properly updated. I also get many "could not connect errors" which are probably related to all of these problems. I haven't been able to verify exactly what is going with achievements; I think that they are tracked, but I do not get notifications.

Basically the only thing that works is launching games, and the only benefit to launching games through Galaxy rather than just opening them up in file explorer is that it seems to correctly sync cloud saves.

If I restart Galaxy it will work properly, for an hour or two with updated statistics that correctly track what I had done on my last session. But then after a couple of hours it will stop working again. Occasionally it will randomly start working again after it stops, but usually it won't start working correctly without restarting the whole program.

Yours will correctly sync cloud saves? lucky

Except that it doesn't do what the older versions of Galaxy do as well as the older versions of Galaxy do them.
And it doesn't do the multi-platform thing as well as Playnite does.
And it has numerous bugs, some of them directly service-breaking.

I can see the potential for it to BECOME a great platform. But it's not even an ACCEPTABLE one to be forcing on users as it stands.

I don't disagree entirely. I think it needs some time before it'll be ready. However, I imagine the features that haven't been implemented yet are the less popular ones so if not for the bugs, I don't see anything wrong with them forcing upgrades at this point.

I agree, why even bother using it at all?

The integration part of the client is a big fail, when many go offline.

Many say they can't do much due to covid-19. And I will say back those problems existed from before.

Features missing:

-reliable access to your game library. (ok actually this is a bug)
-easy forum access from game page.
-a library view where you can see a game list AND a currently selected game on the same screen. (Seriously...)
-light mode and/or high contrast mode (absence of both literally locks a huge portion of users out of the service)

Many other basics are notable by the absence too, but those are some of the most obvious and egregious highlights of CRITICAL features that are missing. All of them have been consistently getting pointed out as major problems since before 2.0 became a forced update. They knew these BASIC REQUIRED FUNCTIONALITIES were absent and pushed it live when it's obviously not ready yet.

And in the middle of a crisis which appears to be preventing support from responding to anything. My current ticket has been waiting for more than 3 weeks without a reply so far. Even if they thought it was ready, launching now was a hilariously stupid idea.

"Forcing UPgrades"????

In what way is it an upgrade to go from a fully functional software system to one that it NOT functional (yet)?

I'd call it a pretty clear downgrade.

I agree, It looks promising, and I appreciate the option to try it out and give feedback to the devs. But it has to be an option. It's clearly not yet a finished product and releasing it as such is not right.

Now I get many replies that my inability to download my games with Galaxy 2.0 must a problem at my end.
Sure, in a way it is: My rig is dated, for sure, but that's why I come here: I use it to play older games (G.O.G. is short for Good Old Games, remember?). And succesfully and happily so - until Galaxy 2.0 came about.
And in another way it isn't: It's ONLY with the Galaxy 2.0 that I have the problem.

So from my point of view, Galaxy 2.0 is the problem.

It looks like it has a memory leak issue, which is of course mostly a problem if you have an older rig with less memory than modern ones. Which would explain why many people don't experience any issues.

But not bothering to test for that (or ignoring the result) sends a very strong signal to people like me, that we are no longer wanted as customers.

And then the silence: There are numerous threads on the forums with hundreds of complaints, even one started by the GOG team themselves inviting feedback - and not a single reply in any of them from the GOG team.