This was the Hunter S. Thompson movie before Terry Gilliam decided to do his version. It's more of a series of episodic vignettes based on several of Thompson's stories instead of being an adaptation of just one. It basically covers Thompson's relationship with Chicano lawyer "Carl Lazlo Esq." during Hunter's attempts to cover Super Bowl VI and the '72 Presidential Campaign, as well as some other crazy shenanigans.
The film doesn't quite do justice to Hunter, his relatiosnhip with Lazlo, or the source material, but it is faithful to the spirit of gonzo journalism and Thompson's nuttiness. Plus, the performances are not too bad. Their far less histrionic than the ones in Fear and Loathing in Las Vegas, but the actos still really get into character, and it's funny as hell watching Bill Murray and Peter Boyle do Thompson and Lazlo, respectively.
This is a chaotic mess of a film, but it is rather fascinating to watch. It's not really a complete success as a movie, but it is entertaining. It's kind of a bummer that this is so underappreciated and not given all that much time of day. You gotta be in the right mood for something like this, but it is worth a watch, despite the flaws.