Pros
Guidewire is a pretty special place. Great technology, a lot of people who really care about building software that works, and a lot of practicality. Bullsh*t doesn't fly here: there is a lot of skepticism around things that make other organizations starry-eyed. Pragmatic applications of unit testing is a good example: we test much better than most organizations, but we recognize there isn't a silver bullet out there, and testing is no substitute for good architecture. We also don't let pure architects exist: if you've got an opinion on something you better damned well be writing code for it. Best crew I've ever worked with.
Cons
We do roll a lot of our own technologies. That can be bad if you want to add the latest J2EE acronyms to your resume. But if you are a general technologist, it is a pretty fun environment. We've got our own langauge, web layer, OR layer, etc. All of it is done pretty well, when compared with the usual J2EE garbage, anyway. We are also tribalizing a bit as we get larger. Probably not much that can be done about that.