For me, the lack of window menu accelerators is a dealbreaker: I'm used to being able to hit alt-space then x to maximize, alt-space then c to close, and so on.

For me, the lack of window menu accelerators is a dealbreaker: I'm used to being able to hit alt-space then x to maximize, alt-space then c to close, and so on. Most windowing systems support these keystrokes. Gnome doesn't, and because the window menu is rendered using a non-GTK toolkit (because of course it is), it's surprisingly annoying to add these accelerators. It's not just this one thing either: every single time I try Gnome, I last about two hours before I run into some random thing I want that the Gnome developers won't let me do because they have Design and Vision and know better than I do how my desktop environment should function. I keep trying KDE once in a while too and hit different issues, usually related to stability or clutter. I miss Unity actually. But it was a huge effort to patch every app to support top menus and launcher badges, and I don't blame Canonical for giving up. Right now, I'm using Cinnamon, which is both unstable and unfeatureful in some ways, but that at least doesn't continually annoy me in ways that Gnome and KDE do.