First I thought the movie was pretty fair. Far more far than Bush deserves or than I would have liked. I would have enjoyed seeming him shredded more. But the movie really looked pretty honestly at his background and motivation. It showed him as a hapless person incapable of almost anything before being elected Governor of Texas. It also shows in much detail his failed search for approval from his father.
The primary feeling I had was sadness. The fact that we as a country elected him twice and he was and is so clearly not prepared or capable of being president.
I thought the characters were fairly close. Richard Dreyfuss as Cheney was probably the closest to the actual person. James Cromwell as Poppie Bush did an excellent job as well. Toby Jones as Karl Rove is even more of a weasel than the real thing if that is possible. Thandie Newton as Condi was not great. Rice clearly has some brains but has totally compromised herself for whatever reason. In the film Newton plays Rice as a mousie dolt. Similarly Jeffery Wright plays Colin Powell as much less of a substantial person then I think he his. Although it does a good job of showing how he compromised himself as was bullied into things he clearly did not believe in.
The movie is definitely worth seeing. But if you are a Bush hater don't expect him to be raked over the coals and expect to actually have a bit of sympathy for him in the end.