Pros
Guidewire has allowed me to where many different hats since I joined 8 years ago. I was in customer support for a year, then I joined professional services for 5 years, and now I am a Product Manager working in the Development organization. It is rare to find companies that offer such career mobility. One of the other things that I appreciate is that our CEO still has an open door policy. If you have any concerns about the future direction of the company, or you don't understand a change in policy you can email him directly. The last part I will comment on is our Product Strategy. We have a laser like focus on serving the needs of one industry vertical: Property and Casualty Insurance. This industry is recession proof, and insurance is product every consumer owns, but rarely really thinks about. I was burnt by the dotcom bubble many years ago, and I value a company that has a real sustainable business model.
Cons
With over 1000 employees, you can't know everyone in the company anymore. It is surprising to get into an elevator, and have someone get off at on the same floor, and you never met them before.