And I find the current behaviour of not switching until you change the workspace fine. Although maybe switching instantly while still showing the small ‘switch indicator’ would be good too, not sure…

- When not all windows are maximised, switching windows “live” would involve shuffling z-order with bits of windows flick in front of or behind other windows. Switching workspaces always involves a full-screen change.

- When not all windows are maximised, switching between windows usually leaves the layout looking more or less the same. Every workspace is usually drastically different in colour and layout from the others.

- When switching windows, you’re being asked to find the window you want from an arbitrary number from two to infinity of them in any possible layout; when switching workspaces you’re choosing from a fixed, smallish number with a consistent, stable layout.

- When switching windows, usually only the window you switch to needs to repaint (and not even that, in compositing mode). When switching workspaces, every window needs to repaint.

Whatever solution is chosen should minimise visual clutter and flicker for each operation.

The ideal window-switching behaviour is probably something like the Compiz plugin where the screen is dimmed and each window is raised and highlighted as you tab past it – you’re only ever looking at the focussed windows, they’re large enough to recognise and more or less where you left them, all aiding your ability to quickly recognise the window you’re looking for. Of course, that’s not really possible in a non-composited window-manager.

Restricting ourselves to things that are possible with traditional X, probably the nicest thing to do is what Metacity does at the moment – show a new pop-up with a list of windows; only update that list while the switching is going on; give whatever hints we can as to window identity (icon, title, snapshot if there is one), only switch once Alt is released.

For switching workspaces, since there’s no dynamic descriptions available we just have to go on their general layout – if it’s possible to repaint the entire screen to show the new workspace instantly, we should do that; otherwise the switcher panel should show large and recognisable previews and only switch workspaces once the modifiers are released.

As to keeping windows mapped all the time, I’ve been bitten before by Compiz’s viewport system, where windows at the left of the first desktop sometimes show up at the right of the last desktop preventing me from recognising the layout of the workspace I recalled.If it’s possible to keep windows always mapped so they never need to be redrawn, and keep Metacity’s current workspace system, I think that would be awesome.