Pros
First off, not for everyone. Expectations are high and direction may be limited. This is not a follow the leader type of organization. Individuals with their own ideas will run into some of the same obstacles to change, but those that can bring those ideas to a group and work with that same group will have unique chances to advance their ideas. If you are looking to follow tasks from 9-5, this is not for you. However, on the other side, a very flexible work place that does not promote "clock watching". You have a high level of expectation and you are given quite a bit of freedom to get there.
Cons
Like any large company, there is a certain amount of beauracracy that is a pain to deal with. The multiple incarnations of Novartis that allow for seperate cultures (e.g. the academic feel of NIBR might not be suitable for Pharma), is also the same dynamic that makes almost every global initiative slow and tedious.