I bought it and I think its biggest strength is feats. There are a lot of good ones in there. One of the problems with a divine character, for me, has always been picking feats that would be useful.
With Complete Divine, this won't be a problem anymore. Lots of good stuff there.
Good prestige classes as well, and the stuff about the afterlife may one day be handy. Unfortunately, since I'll be running Eberron in a few weeks, the new info on the gods will be near useless except for ideas and inspiration.