I have posted a review of Covenants in RPG.net (not the new supplement, but the very old, second edition one, which is available in PDF format at e23.com).
This is the link, in case anyone wants to read and/or comment it:
rpg.net/reviews/archive/13/13512.phtml
Was that 2nd ed? Man, that was the first supplement I bought (on sale, as I was getting into 3rd ed.) It treated Covenants as characters, you essentially bought virtues that gave them stats, and you could roll for them if they were applicable.
Loved that book. Still do (or would, if I knew where it was...) 
Not as thorough and detailed as the 5th ed, but I'd still recommend it, for color if nothing else.
Accurate write-up!