Pros
The upside is that the company builds important products with a fair amount of "gee whiz". Depending on the project, you can have some autonomy. There are some really sharp people. Salary, benefits are very good (1:1 401k match, 16 days/year paid leave).
Cons
If you get stuck on a bad project (i.e. one that is doomed before you even hear about it), it can trail you for a long time. It's my experience that when assigned to a project, some crucial technical decisions have already been made (by people not qualified to make them and who aren't responsible for making the darn thing work). A lot depends on the business unit and location. Some work locations provide excellent environments (offices, adequate lab space) while others are just giant cube farms with PhDs in cubicles. General environment seemed better during the employee-owned days.