Yeh dispell is very useful.

However, it will remove protect which is a pain. You don't need protect against any of the dark aeons - only penance. So if you plan on fighting penance you really do need auto-protect. It's also a lot more useful than auto-phoenix because to be honest - you shouldn't ever die against the dark aeons. If you do you're in big trouble because of the number of turns you miss out on.