Pros
Very intelligent and usually friendly co-workers, hired from some of the top schools in the country. Developers are given a lot of standard tech perks (beer fridges, flexible hours, etc.). Beer is very, very good. Subsidized restaurant in building. Interesting mission of fixing healthcare. Lots of parties and corporate events. Dogs everywhere.
Cons
You get the feeling that all the interesting problems were solved a long time ago. Overemphasis on applicants from "top schools" when the majority of the work is just maintaining ancient code, requiring little creativity. The CEO says frankly appalling things about women and minorities during corporate meetings and people just shrug and say, "Yeah he's kooky isn't he!" Dogs everywhere. Creepy indoctrination for new hires that creates a political narrative for work even as it claims it's not: the CEO is of course in the Bush family. Career advancement is very slow. It is a good place to cool your jets after an intense career somewhere else. Employee engagement is a sticking point as many developers work here until they can try to apply again at Google or Facebook. Bizarre pride in building the company around aging technology (Perl, Perforce) that the rest of the industry has left behind. Adoption of more efficient core systems stymied by political infighting. Very top-heavy, un-transparent HR department. Developers are allowed to exhibit ridiculous behavior while lower-level "analysts" get fired for similar behavior. Diversity is near non-existent in any management position although this is typical for tech jobs. Company reorganizes much too frequently. It pretends it's because "things move fast" here, but really it also "reorganizes" many people out of a job. So so so many meetings, most of them unnecessary. Claims to be a "flat" org structure but that just makes you notice how hierarchical it is.