I've use cinnamon for month till I switch to gnome-shell (again)
then xfce in September. I was always using the lattest version, after 3-5 days cinnamon was just killing itself as the memory leak was encountering 2G...
So I can speak of my last experience of gnome shell.
The install was ok and everything that was available was working correctly, but there was this effect when you open/switch windows which was really annoying. So I though : we're going to change that.
When you use windows, osx, other linux DE it's something you can do. With gnome-shell you can do it but you've to edit system file manually... so I just let it go.
Then there was these shinny extensions on the gnome site, I though perhaps this could help me with the transition. I tried 3, one was doing nothing(I suppose it was broke), one was uggly and one completely broke the default settings.
So it was only three months ago I don't know for you but this is not my definition of stable.
And even gnome-shell team have understood it was a little too much, they always said they were not going to maintain an outdated and gnome-shell breaking experience thing : the legacy/classic mode.
They have perfectly good justifications : moving forward, putting energy in improving their new DE, taking care of their vision first even if it was obviously meaning a massive users leakage. But when you believe in what you do you don't care the critics and they seemed pretty confident at this time.
Do you remember when extensions were introduced ? they clearly said it was not done to reintroduce gnome2 features. Do you remember when legacy mode was introduced ? they clearly said it was not something they were going to maintain but more something quickly hacked in case of hardware problems.
So if gnome-shell is something stable and usable why do they care about reintroducing legacy functionnalities now?
And don't told me they just listen their users, I remember reading on their mailing list that they can't listen because the only users speaking are thoses which are not happy and it's not something relevant.
For the rest I'm ok whith what you said, and again it's just my view. Perhaps if you are somebody who just want something working and who never change settings and don't use your computer a lot gnome-shell is perfect, but I'm inclined to thing this kind of people buy apple laptop instead (like the people you can see at every gnome conference). Oups...