I think it might be the most appealing to people who already have a good understanding about operant conditioning and dog behavior and might be a bit of a slog for people who either don't find those topics interesting or for whom much of the content is new. Operant conditioninig described by anyone can be a bit technical and dry. I do think it's very well worth it to push past the beginning and the good stuff is further in. Just like any book, it might take a bit to "get into it". I did find the first edition with the black and white profile images way more entertaining. I got it out from my local library.
TOEOTL is certainly more readable but less important content IMO.
Some of it is just personal interest. I tried to read Coppinger's book on Canine evolution because I'd heard it's sooo good and I found it sooooo dry and soooo lengthy.I felt like he just went ON and ON and ON and ON. I forced myself to slog through it and some bits of it were true gems and very interesting but holy smokes I wished someone would give me the Coles notes version.