It was, of all the above mentioned, the first to give me a fluid desktop performance with decent aesthetics and all functionality I have grown accostumed to. I'm particularly fond of:
* Alt + drag work really well, specially dragging into borders with automatic resize. The lack of this feature in MATE was a daily pain for me.
* Login screen actually has useful information (even HipChat notifications!) and is really accessible - it opens up whether I scroll or simply start typing my password.
* The search box is, for a change (from Unity), actually smart. When I say "home", it knows precisely what I mean.
* All my tools work perfectly. IntelliJ WebStorm, HipChat, Chrome, the terminal... Even Spotify Linux Preview works like a charm.
I have had TWO minor hiccups:
* Bluetooth needed some extra modules installed. After that, everything worked fine.
* Workspaces would not behave appropriately with external monitor. One command solved that.
So, for now, Ubuntu Gnome is definitely my distro of choice.
[edited for formatting]