How do you disable the window switch animation when switching spaces with Mission Control?

You can disable the animations with TotalSpaces (born ReSpaceApp). Just uncheck the Use transitions checkbox in TotalSpaces preferences.

Total Spaces integrates with Mission Control's multiple desktop system and adds extensive customisation, including disabling animations or adjusting the speed.

It's compatible with OS X 10.10 but requires disabling System Integrity Protection on OS X 10.11.

Change the delay when dragging windows or applications within Spaces.

Launch the Terminal and enter the following at the command line:

defaults write com.apple.dock workspaces-edge-delay -float 0.1

The number on the end represents the wait time - the default is set to 0.75 (or 3/4 of a second), so 0.5 is half a second, 0.1 is a tenth of a second, and so on. If you use the above command and 0.1 you’ll get a near instant switching of spaces.

If you want to revert to the default setting, just specify it as so:

defaults write com.apple.dock workspaces-edge-delay -float 0.75

You can disable the animation that shows up when you launch mission control with this

defaults write com.apple.dock expose-animation-duration -int 0; killall Dock

and undo with

defaults delete com.apple.dock expose-animation-duration; killall Dock

If you'd like to keep the animation, but speed it up, you can do this instead

defaults write com.apple.dock expose-animation-duration -float 0.1; killall Dock

I don't know how to disable the annoying sliding animation when moving between spaces without using mission control, though--as was mentioned above, using ctrl+1, ctrl+2, ... does make that animation a lot faster.

Does this article relate to your problem ?

It advocates this command :

defaults write NSGlobalDomain NSAutomaticWindowAnimationsEnabled -bool NO

For desktop switching, I quote from How can I disable animation when switching desktops in Lion? :

I've just noticed that doing Control+Number is noticeably faster than Control+Arrow. It's still animated but it does complete the animation in about half the time.

Sadly, Mission Control hasn't yet been modified (or the secret preferences to tweak it haven't yet been baked in or discovered.)

You really have no choice other than staying on 10.6 or seeking an alternate window manager like hyperspaces.