The QuickGrid plugin has been updated with a button which will display the current AC3D grid settings when clicked.
http://bellsouthpwp.net/a/t/atomicd/...quickgrid.html
Before this, there was no way of knowing the current grid settings without going to the Settings dialog.
NOTE: The old version has been kept up on the same site for those that do not require this functionality and desire a slightly more compact frame.