I'm sure there's some kind of order, but I can't figure it out for the life of me.

Here's the thing that drives me nuts: in any other desktop environment from ~1990 onwards, if you pressed Alt+Tab once to switch to the immediate next window, and then pressed it once again, you'd be switching back and forth between the same two windows. In GNOME 3, sometimes this happens. Other times, you Alt+Tab to one window, and then Alt+Tab again assuming you'd go back, but end up at a completely different one. And then Alt+Tab again, and wind up at a different one...

I have absolutely no sense for what window I'll get to. None of my guesses for the order have remained true over time. Which, in practice, means that I can't just hit Alt+Tab -- I have to press it and then wait and check which window I'm actually going to, and see whether or not I need to adjust my selection. It drives me nuts.

I'm trying Alternate Tab now: https://extensions.gnome.org/extension/15/alternatetab/

I don't actually might the application window grouping too much in GNOME 3, though I do like the notion of limiting the windows to those on the open workspace (otherwise, being bombarding by all windows kind defeats the purpose of separating them into workspaces). So far this seems a little more sane...