Pros
"Unlimited" PTO* They are family friendly - if you want to see your kid's dance recital at 2pm you're 90% likely to be able to do it. The thing is I don't know a single Software Engineer in Silicon Valley who cannot do that, and I know quite a few.
Cons
*1. They very well might not let you take any of that PTO. That's what happened to me. At least I used to get a check for unused. 2. Subpar pay; you'll need to quit to get paid what you are worth. This gets worse year after year. My team had one promotion (and that includes little ones from Senior Software Engineer I to Senior Software Engineer II) every 40 man-years. That is not an exaggeration. 3. Employees that aren't at Mountain View are clearly happier. Don't hire on at Mountain View. 4. It is a boring stodgy "Enterprise" company. It will be difficult to build your skills in new technologies. Internal training is painfully useless.