FWIW, I think it's a lot easier to work in non-maximized windows on OS X than Windows just because of the navigation. Windows are somewhat thrown around, but it feels very comfortable to bounce through them with cmd-tab and cmd-`. It feels much more natural than full-screen applications. But whenever I'm on Windows, everything's full-screened or, at the least, snapped. The only maximized window on my machine right now (2x27" 2560x1440 plus the rMBP panel) is Parallels, with a maximized Visual Studio inside of it.
GNOME 3 has the same application-switching/window-switching distinction, which I immediately disabled in favor of alt-tab doing window-switching. I rarely have more than one window open per application; the only common exception is Pidgin and its chat window, and I'd prefer if those two windows were docked together.
I can, but it doesn't feel as natural to use smaller windows there. For a very long time, OS X had no real concept of "fullscreen", and I think the predominant culture around application design still sticks by that. I've never willingly used a full-screen app on OS X for anything other than video or Parallels Desktop.
