Pros
The culture is really fun, and the talent is top notch. Upper management came up with many creative engaging ways to incentivize the less glorious aspects of the software support cycle. Growth and learning is encouraged right along with individual, and team performance goals. The technology used is cutting edge, and their focus and commitment to make testable, maintainable code is unlike anywhere I'd been previously. They also pay very competitively against the local market.
Cons
This is an enormously driven group of people who don't hide their competitive natures at all. If you are intimidated by strong, challenging opinions,... constantly, this may not be for you. There is also an aspect of insulation that comes as a result of having such a large application codebase and such great test coverage. This makes change way more difficult than it needs to be.