The reviews here made me doubt about watching Cosmos but I'm glad that I did. Sure, it's a bit slow at times but then again it's not the kind of movie that asks for a high paced action packed script. Yeah, the acting and character building could be better but overall I thought they did pretty good. You could feel the underlying tension from the beginning and I like how you get put on the wrong track (intentional or not) about its source with a couple of scenes that suggest there could be a gay theme to it. Their true story slowly unfolds and offers a useful backup to the main story line.
Some scenes could have been shorter, the music was a bit over-dramatic but all 'n all a pretty good watch, a rather original story and sound acting with (for me) enough depth to make the whole believable and enjoyable. Definitely not a waste of time or space.