I watched it on a plane earlier this year. It was very interesting.
However, you have to consider that it was made by a film maker, not a cyclist, so the way he puts the story together is different to what you may expect. That sounds like a terribly obvious thing to say, but you have to remember that the majority of the audience that this film is intended for, may not aware of a lot of the back story, so I felt he did a very good job of putting together a complicated history into an intelligent documentary.
Also, as mentioned above, he started out making an entirely different film to the one he ended up with, so that in itself makes for compelling viewing.
I don’t think anyone comes out of the story smelling of roses. If anything it just makes the whole sport of professional road cycling look (even more) crooked. At best.
Definitely worth a watch.
There’s a good interview with the Director, Alex Gibney here
http://www.rogerebert.com/interviews/alex-gibney-discusses-the-armstrong-lie