CMG presented additional use cases for ETLAT. CS5 added several more several more features so that now "ETLAT behavior works for keyboard shortcuts for zooming, fitting, previewing, taking and viewing snapshots, showing channels, showing and hiding grids and guides, and showing the current frame on a video preview device."
One shortcut that may be handy is Shift+Esc to toggle between two compositions. There's more in AE Help and in Creating Motion Graphics.
Update: Chris Meyer covered CS 5.5 updates to ETLAT in video, as did Todd Kopriva, and later shared another example from After Effects Apprentice:
After Effects Apprentice 15: Final Project | by Chris Meyer and Trish Meyer