Well worth the money but I agree with others who suggest that there is a lot of repetition in the book. This doesn't make it bad, though. I found it to be very helpful in many areas and pulls together lots of different subject matter very well. The main grumble is that there is NO CD so I can't cut and paste the many snippets of SQL they provide. Still, I'd recommend this book over the competition if you're looking for something on performance/tuning.
On the issue of repetition, I find that many Oracle Series books seem to repeat, space things out well, print long code listings (even of large PL/SQLblocks) etc. It looks like they are desperately trying to write 1000 pages ! I note that one of the co-authors also wrote the Oracle Press reference book for web server which was even worse in this sense.