The objective when I was configuring automount was to have any user be able to access the floppy drive and a digital camera or external hard drive in read-write mode, and the external dvd drive read-only, and to have them automatically unmount.
The first attempt was submount, but when I got automount working properly (there was a bug in the previous version) it just worked so much better, there were no mtab entrys and 'df' didn't try to mount devices that weren't accessed.
I am using version 4.1.3 of autofs (net-fs/autofs-4.1.3-r4)