Pros
You can participate in big projects, working for big companies like HP. Actually it's both positive and negative point. You can learn how such companies are organised internally, know a lot about their processes and might be the most valuable thing is to develop your soft skills. If you manage to survive and succeed working on a multi national big project in HP where teams work from different countries and time zones, you will definitely be able to work and succeed in other companies. Might be it's a very good place to start you career as a manager. Your diplomatic, negotiating skills will be much stronger after several releases.
Cons
The processes and tools might be a bit outdated :). Also you can *enjoy* tight deadlines, working in your spare time and under pressure of several levels of managers. You will learn a lot about risk management when a component you're working on depends on a stuff that should be created by guys from another continent :)