As the new version is now out, and with the price falling, it's excellent.
The selection and variety of plants are great, the pictures also quite good, although with the section on trees, some have the overall picture and others just the Leaf. I found the scale indicators confusing, as the large trees and small are the same physical size just with the scale number different.. hard to build a mental image. I found the insectivorous plants mingled with others when for an encyclopaedia I would have expected a section on its own. I guess as an encyclopaedia I'm disappointed, but as a garden selection guide and reference particularly on flowers, it is very good value.