Perspective from a middle of the pack, both in terms of job level and employee count
Pros
The people are pretty fantastic, as are the perks -- food, HR really does have innovative ways of taking care of you, transportation options. Google has been willing to open up offices where its people want to be, which has been great. There is a lot of opportunity to travel, and communicate your vision to a wider audience. I appreciate some of the hard work that has gone into building the culture and Google tries hard to maintain that. There is a sense of legacy and that great things are yet to come. This is not something that is easily sustained, yet there is so much effort here, that it just might work.
Cons
Certainly it's a big company. It tries hard to not be. It tries to rekindle some of the old things that made it unique, but it seems like a lost cause for the most part. There is much less opportunity to shoot to the top. There is less and less exposure to people outside your organization and too far above your management chain. There is a lot of work to be done, and Google is pretty cheap about the way that work gets accomplished. It puts added burden on many people including engineers and lower level managers. Getting actual things accomplished and seeing how it fits into the company goals has been hard.