While testing other desktop managers on my laptop running Ubuntu 16.04, I've accidentally broke my installation.
The main culprit is me as I did force a few things to happen. Ubuntu has been my main distros since 2004. The passage to Unity did upset me a little bit but I got used to the new interface and eventually, I liked it.
Today, I wanted to try out the other desktop manager available in the Ubuntu repository. I could not get a decent performance from KDE, but others like XFCE and Mate were running smoothly on my old laptop.
Eventually, I've tried Gnome... I was expecting something similar to Mate with a few bells and whistles on the top. It's not a lightweight desktop but it does have its charms. I must say, I do like this desktop metaphor way more than Unity.
The way I understand it, an app is meant to run in full screen all the time. That is something that I do like in OS X as a full screen app is considered as a "new" desktop space. That's exactly how Gnome 3 does work.
Of course, you still can have multiple apps running in the same desktop space, but I hate switching between apps as I do prefer everything to be maximized. The the Unity Desktop, you can have multiple desktop spaces but you have to pre-configured the layout. In Gnome, desktop spaces are dynamic so if you need one more, just go to the last desktop space.
Another great feature of Gnome is the Gnome Shell itself. It does support Extensions that can be added at the top and I've found a few plugins that made my day.
Finally, I just re-installed the Ubuntu Gnome from scratch to ensure that nothing from Unity would survive on my laptop. It is a bit more flexible than Unity and does provide a lot of features.
You can download for free at: https://ubuntugnome.org/