Just finished the Director's commentary on my TTT extended DVD. Jackson & Co. defended their choices quite well. Dunno, following the book word for word would have made for a more boring movie IMO. But then, I loved TTT anyway.
Incidentally, did you catch the acknowledgment that they have had second thoughts about their handling of Faramir? The comment was made by the women sitting in with PJ during the directors' commentaries. The gist was that they were trying to flesh out Faramir with backstory and perhaps "lessened the character by expanding him," which I think is a pretty fair assessment.
I'm not inclined to be overly critical on this point. They had to make many judgment calls. I'm sure there are more than one they'd like to have back, but you can't second guess yourself forever.