Im a big fan of Steven Soderbergh, but this was not his best. (Not even close). Contagion is not so much a movie as it is, “this is how it will play out infomercial” kinda thing. Yes, there will be those who are immune. Yes 911 will stop answering at some point. Yes, its important to track it down to patient 0 and where did they pick it up. This is a quarantine. Vaccines take time. Normal people begin to act irrationally very quickly. Maybe you should own a few guns. Maybe you should stock up on food.
In that sense, as well as the biology lessons, and the disaster scenario it was informative and worth watching, but I would say this is more of a rental. Not much of a story, no character development and it is hard to connect with any of the leads. Many loose ends.
If you do decide to see it in theaters, you can spicen things up a little by coughing uncontrollably about an hour into it.