I have installed gnome-session-fallback. I followed Håkon A. Hjortland's excellent instructions from How to customize the gnome classic panel, but autohide (and even more importantly unhide) is still at the default overly slow speed. How can I set the unhide speed of my top and bottom panels?
You need to use dconf-editor from the package dconf-tools and set the properties manually. When the package is installed, press alt+f2 and run dconf-editor. Find Org > Gnome > gnome-panel > layout > toplevels. That will contain "bottom-panel" and "top-panel", each with its own settings, like animation-speed, auto-hide, auto-hide-size, hide-delay, etc.
Play with those settings and restart gnome-panel by pressing alt+f2 and running