I think I liked the film more than you, although I haven't read the book since it was first published, and have forgot most of it, so I don't remember what the changes were.
As for the transfer, I only saw it on a standard TV, but I thought it was very strong. The film was financed by the Voom HD network, so I don't know if it looks better on a better setup than I had, or in HD.
I watched the disc on a Sony 40" XBR2, playing on a Playstation 3 with the current software upconverting the image to 1080p.
It's a fine transfer - but I temper that with the fact that the film was shot for 500K in 18 days. I also believe it to have been shot on HD cameras, but I have been unable to confirm this.
And I'm truly sorry to not be able to write more upbeat reviews of this film or of Charlie Wilson's War, but I've got to be honest with you and with myself. When I see one that I really like, such as Breach or Breaking and Entering, you tend to see me writing in more glowing terms.