I saw it yesterday. Loved it. (Cried and cried.)
The resemblance was amazing. I was particularly impressed by James Brolin as Dan White. Since I'm concurrently watching "Brideshead Revisited" on the Arts Channel, I also found a similarity between Kurt and Jack Lira (Diego Luna).
I was impressed by the way they merged documentary and re-enactment footage. It was hard to tell which was which. I think they colourised and "grainised" some of the re-enactment footage to make it look like 16mm film from the 70s.
Historically, one major event they left out was the Jonestown Massacre, which happened nine days before the Moscone/Milk assassination and involved many people still in San Francisco, including Moscone and Milk, who had supported Jim Jones and the People's Temple.
When I was in SF in 2006, I made a point of finding the site of Castro Cameras, and here are my pix.
The first looks north up Castro St towards the Harvey Milk Plaza (where the big flag is), taken from the shop doorway.
Harvey is commemorated with a mural that is a trompe l'oeil window next to a real one.