I have my Winbox windows pre-defined in my session preferences, so every new session opens with my preferred windows open in exactly the same place and dimensions each time.
If a window ends up behind another, I don't go looking for it in the right-hand pane. I navigate to it through the menu again.
For example, if my interfaces window is behind the log window, I simply click the interfaces button again to bring it to the foreground.
I wouldn't disagree with adding a minimize button, but I doubt I'd use it much because it's just as fast to bring most windows to the foreground via the menu on the left.
Yes, i also use the pane menu to reopen window too.But think about the follow condition:
1.some window when you reopen it, it will open new window instead of bring the old one back. eg: terminal window
2.sometimes you can't get back the window which you want by reopen it in pane menu. eg:
2.1 double click a interface item in interface list window, it will open the interface property window
2.2 this time you may be want to reference something in the other window, then you switch to that window, and the interface property window completely behind it.
2.3 now how do you get back interface property window by the pane menu? open the interface list window then double click the item again? I don't think it's effectively.
3. When you want to switch to a window by pane menu, first you should take a short time to think about where the menu item is(even though you may very very familiar with it),
then you click the main menu and the sub menu. Take a think about if you need to switch two window again and again or switch among many windows and they are in different menu.
If winbox has the hot key (eg: alt+tab, common in win os), you just to press the hot key and never think what window you are looking for and what the menu should open.
I also think the winbox is profession and powerful when compare to others. But there also some features to be improved, especially window switch.