Pros
Incredibly smart and talented engineers. Great people overall: very passionate about what they do and generally very dedicated to the job and their employer. Very cool technology at an incredible scale on the infrastructure side. It's a great machinery. Ability to see all code and work on anything you want, at least as a 20% project.
Cons
Working from outside Mountain View can be tough: from late hour meetings, to generally having at least 20% less influence/impact than you'd have if you were in Mountain View, especially on the making decisions side and driving projects. Fair amount of politics and fighting for key projects, bad co-ordination between teams working in similar areas. The occasional suck-up and getting promoted if you're vocal. But I wouldn't say that's the norm though. Low salaries compared to quality of people and hard work done. High difference in salaries depending on where you came from and how good you were at negotiating them. Very unscrupulous at negotiating everything when it comes to money (from salaries to anything else). Very unscrupulous at using their brand and positive image advantage to the maximum in such negotiations. They treat you like you always have to give something up from your side for the privilege of working with / for them.