I had this text for my Physiological Psychology class in the final semester of my 4-year undergraduate degree and it was the single hardest text I had to read throughout the four years. At the end of my degree I have a GPA of 4.0/4.0 so I'm no dummy; the problem was not my ability. It used to take me about 10-12 hrs to read a single chapter because it was such hard going. The material covered in this text is very complex and made even more difficult for a learner to comprehend because the writing is unnecessarily complex and there is inconsistent use of terminology (although I acknowledge that that is partly a feature of the neuropsych field).
On the other hand, my prof, who has published plenty of peer reviewed papers in neuro-psych journals but isn't exactly the pinnacle of clear communication either, said that the text did a good job of summarizing the breadth of material in a field that is currently exploding with new findings. He knows the field better than me, so I'll take that to be reasonably true on his authority. I can't compare this cognitive neuropsych text with other cognitive neuropsych texts because I've only studied this one, whereas he has taught from several over the decades he's been lecturing. After wading through the hellishly-dense language, in the end the content was very interesting and I could definitely see the practical implications of the science. After finishing the class I am able to very comfortably comprehend neuropsych reports in the popular science literature and I can limp through the peer-reviewed research reports, so I must have learned something from this text, with a little assistance from the prof.
It has most of the usual features of good textbooks these days: explanitary diagrams, images, charts, chapter-end lists of key terms (although I found the glossary to not be thorough enough), excellent bibliographic reference that I relied upon a few times (gotta love that free access to journal articles thru the university library)... but plain English is NOT its stong point.