I will help you remember:
The terminal command:sudo defaults write /Library/Preferences/com.apple.windowserver Compositor -dict deferredUpdates 0
is for disabling BeamSync. This speeds up performance with LCD monitors.
To enable QE2D, you should run QuartzSimple, enable Quartz Extreme 2D and then Force Quit QuartzSimple. If you simply quit QuartzSimple, it will disable QE2D as it quits. See the first posting of this thread.
There is an edit to be made to the windowserver.plist to enable QE2D, but I don't know it off the top of my head.
sudo defaults write /Library/Preferences/com.apple.windowserver Quartz2DExtremeEnabled true
Also handy commands:
plutil -convert xml1 /Library/Preferences/com.apple.windowserver # to use with textedit
plutil -convert binary1 /Library/Preferences/com.apple.windowserver # to put it back to normal format