Got my copy today. I am exhausted from carrying it from the front door to the living room

It's B-I-G.
Can't really absorb it all in one sitting. The hundreds of photos in the book take some digesting, as do the later blurbs about each tree in the back. It will take repeated sittings to really appreciate it.
The photos are outstanding and there are some quibbles to be had, but overall, it's impressive -- other than the sheer size, number and quality of the photographs. The number of oustanding trees is phenomenal, especially the trees from Japan and some of the lesser-known specimens from American collections.
I found myself trying to guess where each tree came from. The hundreds of tree photos are provided with no explaining text, only images. The book places all the trees -- regardless of origin -- together without comment side-by-side. No "Japanese Trees" or "American Trees" sections as is the usual case. I don't know if that was intentional, but I found it interesting in that American natives, Japanese "name" bonsai, including Kimura's trees, are seen together without any "predjudicial" information that might skew the viewer's appreciation.
Sometimes it is very hard to tell where a particular tree came from. In other cases, it's blindingly obvious.
A few quibbles--lighting is good for most trees, but in some instances (and this is mostly for bonsai fanatics) trunks are obscured, or shadows hide what could be spectacular branching and other details. I wished there were some reference point in each photo to gauge how big or small each tree is immediately (each tree's dimension is listed in the blurbs in the back, though).
Those are only small things though. The amount of effort this took to put together must have been enormous. Hat's off to Bill, the photographer, and co-contributors.