[JKT]

Frankly, I don't see any functional difference between the two at all other than:

1) The drawer allows you to drag and drop to the area behind the window far more easily owing to the gap at top and bottom.

2) It lets you have a larger toolbar (e.g. with ruler active in OmniOutliner) without using up more vertical space in the drawer (a pane would lose that vertical space).

3) I can easily have it on either side of the window.

4) Except in the one extreme case where your window occupies the full screen, rather than shifting content left and right every time you open/close it, which ruins your visual tracking of the content in the main window, it only moves itself.

I can't see any advantages to having a pane and by getting one, you lose all those advantages that the drawer has.

What am I missing about paned views that makes them better than drawers?