Pros
Intresting technologies to work for; good prospects for continuing education. Had chance to work with some really bright engineers when I joined, and maybe you too will get the same, if placed in the right group. Headquarters seems to be a better place than folks in remote outposts.
Cons
Poor career growth propsects, management head in the sand. Older engineers with limited intrest in modern technologies get to make all the decisions; lots of political infighting. Lots of groups are resource hogs with no productive output, but manage to get funded because of the close ties with upper management (in most cases those guys rose from the same groups). Very hard to shine technically. Stopped access to IEEE/ACM libraries as part of cost cutting, and still have the gall to call themselves an engineering company