I second the opinions on Dishwater Boggett. In the book, he was the top hand that all the young cowboys wanted to emulate, who also happened to be in love with Lorena. In the movie, it was almost completely the opposite, as if he was a guy in love with Lorena, who just happened to be on the drive as Hat Creek's point man and top hand. That was a little disappointing, but with an epic novel such as Lonesome Dove, there would have been no way to properly develope each and every character (I think McMurtry said one time that had the movie been made like it should have been (just like the book) and not under cinematic constraints, it might been 5 times as long).
I would love to see a full-screen version of Lonesome Dove, but it just wouldn't be possible. Tommy Lee Jones and Robert Duvall absolutely made that movie, and without them as Capt. Call and Capt. McCrae, it would not be the same movie.
One other question for those of you that read "Comanche Moon"? Did it bother you, like it did me, that the events that took place in Austin in that book were basically transferred to the town of Lonesome Dove later on for the Lonesome Dove book? Gus, Call, and the rest recollect about events and people (like Newt's mom Maggie) and associate them with Lonesome Dove, but that period of the saga actually took place in Austin, according to Comanche Moon.