Second major advantage is that LJ archives everything, and you can go back and read all old stuff. That's such a useful and valued thing - you don't realize how important it is, until you over-use Facebook and then realise that all those great conversations are lost in history!
Combining the above two items, in LiveJournal you can link to previous entries from current ones, creating a hyperlinked network entries.
In most areas apart from these, though, Facebook is much easier to use, more fun, and more versatile.
P.S., of the 41 people who started this classroom + physical training course, 16 have been sent away for medical reasons. The longest hospital-stay of a course attendee is one week, and, tomorrow is the biggest physical test yet. Wish me luck! Also... after the gruelling work in the morning, we have a test on the classroom work we've been doing (think: self-help business-management type stuff - sometimes useless, mostly meaningless, and common-sense to anyone with a brain).