For many products there is a way to separate out the reviews, although it is not obvious how to do it:

Click the "nnn customer ratings" to get to the review section.

In the barchart on the left, click any of the "n star" or "nn%" links.

Above the reviews will be a row of dropdown lists, which may include "All formats" or "All styles" or the like. There you can select the individual product variation. You can also change the "n star only" to "All stars" to get all the reviews for that variation.

Unfortunately this doesn't work for the book being discussed here.