I bought the Nikon D2Xs 12.4 Megapixel Digital SLR Camera a few weeks ago, love the camera. Possibly best camera I've ever owned (of any brand,) should have done it a long time ago.
Thought it would be wasteful to drop $4K on a camera and not know every feature, so I bought a copy of this guide. Pretty disappointed.
Honestly, if you buy the D2Xs and need the guide to explain ISO and F/Stop why did you buy this camera? This is a professional piece of equipment with hundreds of pro-level features. Much of the good information in this guide is already in the manual.
I was worried the moment I opened it up and looked at the included "quick" (useless) reference guide. Instructions on how to change ISO...what!?!?!
I wanted a book that would give blow-by-blow "what is it good for" information on each feature -- for example, the section on HighSpeed crop talks about how it effects the camera's operation, compares and contrasts it for use in action and macro photography. Pretty good. The section on autofocus modes and CLS are the same as the manual -- no detail requiring lots of practice and effort.
It has high and low points. Some good info, lots of filler.