Pros
Mobility within the company is a must. If you are not satisfied with your current assignment, it is relatively easy to move to a more satisfying position. Employees are encouraged to change assignments every few years so as not to get bored. Also, P&G takes care of its employees in ways that I have not seen in other companies. They also live what they preach - at the work sites, you see ONLY P&G products to be used - spilled something in your office? - there is Bounty paper towels nearby. Have a runny nose? Puffs are on your desk. It is little things that make the day to day worth working here. Very flexible work plans and schedule options - especially for scientists. Further, I've only run into a few people that I couldn't trust - everyone else operates at an expected level of integrity and honesty that "business games" or office politics rarely get in the way of the ultimate team goals of improving the products P&G makes. Finally, if you eventually leave the company, you have a HUGE gold star on your resume.
Cons
Masters Degrees and PhDs (in a scientific field) are sometimes undervalued compared to an engineering degree. Further the respect and monetary compensation/advancement opportunity is not there that you would otherwise get in an academic research setting or a phamaceutical company. Also, this is a high energy, high output job. If you want to be challenged in ways you didn't expect - this is the place for you, otherwise don't even think about it. Engineering is generally considered management while scientists (non-engineers) do the "grunt work." in the labs. Eventually if you get high enough - you are expected to move up or move out.