Pros
Good flexitime, most managers competent and laid-back, far better male/female balance than many tech companies, family friendly. Opportunity to work on products that can make a positive difference in the world.
Cons
Limited opportunities to work on customer sites, poor visibility into what's happening in the rest of the organisation. Use of mostly in-house tools can limit acquisition of useful skills and little emphasis on technical skills training. Product is v large and build times etc can be an issue for productivity. The fact that you're working on a framework that needs backwards compatibility and with custom tools can severely limit options when developing. Fairly monolithic product and little chance to diversify into other products. Insanely annoying bureaucratic annual review process.