Re: On the face of it
Whichever release started the Unity default is when I opted out for Mint, and its Gnome 2 choice, then Mate. I do not care for UI change when what I am used to is not broken (for me....). Although I did just recently find a "fix" for one nagging UI issue, the total lack of window borders that I can actually "grab" easily with a mouse/trackpoint for resizing. It seems the Crux window style (and a few others) actually has a discernible border (maybe only 2 pixels? I did love Windows up through XP with its almost infinitely resizable borders).
As long as Mint keeps Mate, and does not eff up any other way, I will not change again.