Pros
Individual contributors are the heart of the company. They maintain the culture and are a highly collaborative group. Bill and Dave's ethos is still alive (but time is slowly eating away at it). There is a flexible work environment and most managers respect your personal time. Benefits are definitely good, but not great compared to other fortune 500 companies. HP provides excellent bonuses when times are good. Internal promotions and career advancement is excellent at least in my group. It's the best I've seen at any company. Small exception is that if you are on a senior technical track you'll be stuck since almost all senior technical roles get externally hired.
Cons
Management is complacent and slow. There doesn't seem to be much drive than to maintain the status quo. There doesn't seem to be any management or oversight of management. There needs to be more leadership and vision, and less short term urgency. Meeting hell. We'll talk it to death, sit on it, then over complicate it and under fund it, and then not understand what went wrong when it fails. Boom/bust cycle. When times are good almost any one can get an HP job, when times are bad there are mass layoffs and disruption. We call people who have worked at HP for > 15 years "survivors". There is a LOT of talk about innovation, but reality is that HP's big company policies and slowness ensures anything worth innovating on will slowly get starved and under funded allowing competitors to sadly out complete.