The story for this film was solid, if straightforward, depicting the Manson family murders and a few post-murder interrogations, with a sympathetic nod to Manson's early life. The dialog was serviceable at best.
The biggest problem with the film is the casting. While Ryan Kiser bears a passing resemblance to Manson, he lacks the sinister gravitas needed for the role. He comes close at times but overall he's just too innocuous in both looks and demeanor.
The Manson gang is even more poorly cast. Their acting is fine when it comes to the line readings, but they're generally too old for their roles and are unconvincing as hippies. The victims are also badly cast and all the characters are poorly developed. Manson's lawyer is the only convincing character in the lot.
The locations are meager. The "upscale" dwelling of Tate has the same sickly yellow walls as every other house in the movie.
All that said, if you want to see a basic depiction of the crimes, this one is fairly accurate.