Pros
Although some of the usual corporate bureaucracy has crept in, Guidewire is remarkably transparent, non-hierarchical, and rationally managed for a company with over 1,000 people. The management of the company has been very stable for close to a decade. There have been a few top-level executive changes (including very good ones like Mike P. and Scott R.), but the mid- to upper-level managers are almost entirely grown from within. For example, the entire second level of services managers have been at Guidewire for at least seven years and came up through the ranks. The same is true of the development organization. As a result, the culture has been very stable over the years. There is a tremendous level of commitment to customer success that is felt throughout the organization. It's the kind of thing that every company says they have, but at Guidewire people really believe it. Marcus is a fantastic CEO: very approachable, very clear, a great communicator. From an overall business perspective, Guidewire is doing fantastically well for a company you've probably never heard of.
Cons
The company has challenges keeping up with growth in a few areas. With added business complexity, it's getting harder to make prioritization decisions, and harder for employees to understand how all the pieces fit together. Some policies have been unclear, like the one for consultants on transfers from one region to another. (That one in particular was recently fixed, but there are probably others.)