I would not consider "W" to simply be a "chronicle of the life of George Bush." The movie was decidedly biased and portrayed President Bush in a mostly negative light. Whether I agree or disagree with Bush's presidency and the choices he made (both in life and in his career), I found the movie to be distasteful and irreverent to the office of the president, a position in America that citizens should respect.
"W" portrayed Bush as a "dumb southerner," a "good ol' country boy," and generally an idiot. However, to become elected to the highest governmental office in the arguably the most successful country in the world, these qualities could certainly not be as predominant as this movie portrayed them in Bush.