There's constant name dropping and random historical information. Stories about the discovery of various mesons, or all the notes about nobel prizes that were won, are just pointless. And descriptions of the confusion before the Standard Model do not aid in understanding the modern theory at all.
There are some major diversions explaining old theories that aren't really necessary. For example he goes through a big section on the "Eightfold Way" which is a historical artifact that doesn't need to be taught in modern explanations of the Standard Model, as it introduces an apparent SU(3) symmetry of u,d,s which is not the real SU(3) symmetry of quarks and is thus unnecessarily confusing. One of the big mistakes is that he spends a lot of time talking about "isospin" as nuclear isospin (proton-neutron identity rotation invariance), but then changes and finally admits that is not the isospin of the standard model and introduces us to Weak isospin.
One of the big mistakes in the book is that he is constantly introducing not-quite-right simplified explanations of things which are really not any simpler, and wind up taking more text to explain the same thing.
He also randomly uses non-standard notation, such as calling the group of rotations in 3 dimensions R3 instead of SO(3) , and he weirdly refuses to explain things, such as using the term SU(2) but noting "the S stands for something technical that we don't need to bother with here". What? Just say it means length-preserving.
I think the explanation of group theory in the book is disappointing. I think lay people can easily understand a lot about groups, and more time should have been spent on this. Even concepts like building up macroscopic rotations by applying infinitesimal ones over and over could be explained.
Worst of all I think a great opportunity is missed. Feynman's QED is a brilliant shining star of explaining the quantum field theory of U(1) in a non-mathematical way, which actually builds up a physical intuition for the reader in a very non-intuitive topic. The author could have focused on the geometry of gauge fields and fiber bundles, and what an SU(2) gauge field is like intuitively. We have an intuitive for what electromagnetic forces are like because we can see them at macroscopic scales, but what would an SU(2) gauge force field be like at macroscopic scales?
If you want an intro to particular physics without mathematics, I can still only recommend "QED". If you want an intro to gauge fields, I recommends Baez's "Gauge Fields, Knots and Gravity".