Mac differs between switching windows and applications.
So if you work in an IDE, keep reading docs in one Firefox window and test your application in another Firefox window then in KDE or XFCE or another sane windowing system[1] - even Windows - you just use alt - tab.
On Mac you have to stop an think: Should I switch to another browser Window? Ok, that is CMD - backtick. Switch to or from IDE? That is CMD - tab.
Press the wrong combination? Now Cyberduck has entered the mix.
[1]:I was about to write Windows or Linux but starting with Unity and now also Gnome has copied this to be bug comptible with Mac
Also the whole paradigm breaks down on macos if you have multiple desktops. Suppose you have one terminal open on desktop 1, and a browser and terminal on desktop 2. From the browser, if you cmd tab to switch to terminal, it will never go to the terminal on desktop 1, even if that was the last window in focus.
Personally i like how Window Maker does it: you can switch between all windows like in Windows, KDE, XFCE and most other floating window managers (by default on Alt+Tab) but you can also switch only between the windows of the current group (usually all windows of an application belong to the same group) or quickly toggle between the last two workspaces (what WM calls virtual desktops). The last two aren't bound to keys by default, but personally i have those set to Alt+` (sort of taken from when i used a Mac for a while) and Win+Tab respectively.
The only annoyance is that it doesn't seem to distinguish between window types so, e.g., in GIMP in multiple window mode it also cycles between utility windows like the toolbar, options, etc instead of only the image windows - though some applications do not even bother providing window hints about their window types.
So if you work in an IDE, keep reading docs in one Firefox window and test your application in another Firefox window then in KDE or XFCE or another sane windowing system[1] - even Windows - you just use alt - tab.
On Mac you have to stop an think: Should I switch to another browser Window? Ok, that is CMD - backtick. Switch to or from IDE? That is CMD - tab.
Press the wrong combination? Now Cyberduck has entered the mix.
[1]:I was about to write Windows or Linux but starting with Unity and now also Gnome has copied this to be bug comptible with Mac