Well, there's your problem, right there. Why would you expect significant mathematical treatment in a watered down version - indicated by "for Engineers & Scientists"?
The title of the other one sounds right. Don't worry about "mixed reviews". Remember that some people hate statistics and wouldn't dare write a positive review.
Why are you in the for "Engineers & Scientists" class? Maybe you should change your registration.
What level are you trying to learn? The second book does not appear to be an introductory course. There is some tedious consideration in an introductory course. This may be what you are seeing. There is some value in getting used to slogging through mounds of data.
Just a few hints...