Outlook is really nice when it comes to system migration and backup. Do a search for *.pst and backup this one file and all your mail is saved. If you change over to another system it is quick and easy to import the old pst into the new one. Still it is true that most of us do not fully use more than 20% of the features.
I use Outlook 2002, and I must admit that Outlook Express has many of the features Outlook has. However, I would still reccomend Outlook 2002. If you don't need a feature... Well, just don't use it. If it's something like the journal or the calander, just delete that shortcut from the Outlook bar.