Pros
P&G is a company that has established value system called the PVPs. They are really proud of the value system and demand everyone follow it. Frankly it does make one feel good to work in such an environment. P&G is a marketing driven company, however, some of the power is shifting into Finance as I've personally seen low level finance managers go toe to toe with senior leadership and win. Overall I do think its a good solid, if conservative place to work. I'd highly recommend it to people who are looking for good pay, good benefits and low risk, but not career ambitions.
Cons
Like all large companies the politics can be brutal. Its important to have your advocates otherwise you are in big trouble. Its also easy to get lost in the system with the organization being so large, which enables some people not to carry their "fair share" and can be frustrating for folks who are working their tails off (or at least feel like they are). Career progression is very slow and i know many folks who have left frustrated at the lack of advancement and were very successful doing so. P&G is a machine and anyone lost can easily be replaced.