I haven't tried either of the v7 books, but I have both Poser 6 Revealed and Practical Poser 6. The 'revealed' book was a disappointment to me - very simple coverage, didn't go into the more advanced aspects very much at all. Deecee's book was much better and by all accounts this edition is better still.

In the end, it depends on what you level you are looking for of course.

Steve