Pros
On the whole, AstraZeneca has great people. There are a lot of smart people, particularly in R&D, who know their jobs and actually like working *with* other people. If you're interested in healthcare or scientific research, want a seriously challenging career and are among the best at what you do, AZ is a good place to spend your time... AZ also takes work/life balance seriously. So if you have a family, whether that's children or parents or siblings, AZ management tends to be sympathetic to those needs.
Cons
A more complex web of matrix management you won't find outside of a government bureaucracy. This provides a huge cost in speed of decision making and in accountability. Giant patent cliff is coming. Heavy reliance on outsourcing (though this has good points, as well as bad).
