I totally agree with you... Movie!Faramir was confused, torn, and somewhat rude in TTT, but in RotK he was decisive, sacrificing, and altogether lovable--much like Book!Faramir all throughout LotR.
The article
What Happened to Gallant Captain Faramir? is absolutely fabulous. The link to it was posted awhile back by
Elladan and Elrohir, in
this other thread. I think you'll agree with what the author had to say.