Pros
Challenging everyday work. Opportunities for professional growth (really, lots of tech talks, people like Sanjay Ghemawat, Rop Pike, etc that you can talk every day in the hallway, invited guests (like Joel Spolsky, Guido van Rossum)), tons of great trainings, interesting projects). Awesome perks. Again, great people working with you. Again, people who are really enthusiastic about work they are doing (e.g. we have weekly whisky meetings where we share and discuss work challenges, news and achievements while having glass of good whisky) We organize white paper read clubs and discussions, and so forth. Sergey and Larry entertaining you every Thursday discussing what's happening in the company and answering your questions. 20% projects (they are not dead, you can always come up with creative and useful stuff and people welcome it). Strong nerdy/engineering culture.
Cons
Google is a big company now. It's not a startup and you won't be making $millions (but you will be comfortable). Sometimes management have product decisions that even most of Googlers do not approve.
