I have both, and I agree with the fact that the 8-ball Bible is a more thorough tome about 8-ball-on-a-barbox than Phil Capelle's book. However, I wouldn't go as far as to say one should throw Phil's book in the trash. (Phil's book is quite good, and is a good "general purpose 8-baller's guide.")
What are true, are the following:
1. The 8-ball Bible more thoroughly covers the game's ins and outs on the barbox. There isn't a more comprehensive guide to this specific game on *very* specific equipment than this one.
2. The chapter on the various barbox cue balls *alone* is worth the price of the entire book. The author first explains the differences (heavy Red Dot cue ball used on Dynamo "trap door" tables; Valley tables with the Aramith green-logo'ed magnetic ball; slug/core balls; etc.), shows you some shots, explains where the shots are useful, and *then* gets into the physics of why things happen that way, if you choose to read that far. He will have tempted you with enough knowledge about how thing are happening the way they are, though, to cause you to want to know more.
3. All chapters are set up that way. In other words, as you read the chapters, you first see something useful/unique, you see examples that you can use right away (in other words, you can stop reading, and go right to the table to try it out), and only if you're interested in knowing more about the "hows" and "whys" do you continue to read.
4. The author's writing style is very engaging -- as you read, you'll find you're hooked.
Like I said, this book is a "Chilton's Manual" for 8-ball on a barbox. There's no better guide to *this* game on *this* equipment.
-Sean