I tend to agree that Complete Warrior is a bit better than Complete Divine (partly just because CD's editing is really rough), but there's some cool stuff in both of them. For me, there's more than enough new stuff to justify owning the hardcover splats and the old ones, and it's nice to have the revisions.
If you're not sure about it, pick up the one that sounds more interesting to you, give it a read-through, and then decide whether or not to pick up the other.