Ventajas
The benefits (time off, health, dental, vision) are decent. In general, you don't have to work a lot of overtime, and there isn't much stress associated with the job. You'll find most people are fairly laid back about there jobs, which makes it easier to go about your business. It can be fairly easy to move around to other positions or location within the corporation. It's a huge corporation, so you can usually find many other opportunities from within if you look hard enough. There is often opportunity to travel also. That doesn't mean travel will be to a place worth going to, but it could. They offer several learning opportunities, some of which can be useful. The name recognition could mean something also depending on your future plans.
Desventajas
The pay is low compared to others in the industry. There's no bonuses for anything and the only thing that matters is the number of years of experience you have. No one measures ability. There's too much middle management and most of them don't know what they are managing. The amount of bureaucracy is quite high. You are rarely asked what you want to do and never given options. Politicking is a necessary skill. Engineers are literally treated as numbers. The corporation is so huge, the left side doesn't know what the right side is doing. It's disheartening really. A lot of people seem to not care about the engineering and care more about climbing the ladder. There's not much innovation going on. With so many people, it seems the skill level is lower on average, though you will meet a few brilliant people as well. The corporate culture is not very upbeat, but it isn't so bad if you work with people who are more upbeat.