heh, yeah, I feel that the books are simply too wordy, his style is really lengthy, and as I am a slow precise analytical reader (I'm used to almost exclusively reading physics textbooks and writings where basically half the thought process is omitted and the reader is required to really do a chunk of the work of reading...) it's been a particularly slow process.
I've heard that the Randall Woods book is written with a little more emphasis on Lyndon Johnson's passion for the poor and positive achievements. Caro certainly doesn't ignore this, but he makes sure the reader has little doubt about LBJ's more nefarious endeavors. And as Caro is centrally interested in power, it's no surprise that he would focus a lot of time on the so often ignored realities about the types of personalities that so ruthlessly seek and execute power. This brings me to what I suspect Bill Moyers would say about the Path to Power. I suspect he would find Caro's extensive research to be particularly enlightening, fascinating, and would probably agree about the conclusions Caro comes to in regards to Johnson's motivations, personality, and confusing oscillation between cruel inhuman behavior and occasional altruism.
But as you say his tone changes during the course of his research, it's possible that Lyndon might also have changed for the better in the course of his life development. It's also of course possible that starting at the chronological beginning of Lyndon Johnson, as Caro did, as opposed to the end, as many who study LBJ simply as a means of understanding the Great Society do, leads to different takes on the same material. And of course, Johnson's greatest achievements seem to have come at the end of his career during his presidency, but also, of course, the great evil that was American involvement in Vietnam. With more of a focus on this period, different conclusions could be made. No doubt, it seems that experts like Moyers and Caro seem to have a similar message and probably only differ in minute detail.
Being in Houston, I can't wait to finish the book whereupon I intend on visiting the LBJ library in Austin (I've been to Johnson City and the Johnson Ranch when I was younger, but as I had no reason to appreciate LBJ then without an education, I am probably going to try and visit the area again.)