I did interviews at google, yahoo, and a couple of the other big Bay area places. I almost accepted some job offers, but the local area was very competitive, so I stayed put.
They were very professional, very serious. But I cant say I was really impressed. They didnt really go into what your background was or what you did in the past. They didnt want to see coding examples. They just wanted to get though their questions. And I remember them taking hours and hours of the day every single time. It was VERY time consuming. The offers also were very stock heavy but not much else.
Later on, it dawned on me that the people that got the jobs out of my circle within university was the ones that "Studied" the questions. They are doing well for themselves, but I don't think a single one lasted for more than 3 years, they all eventually got jobs in other companies. 2 got laid off on a single division, another guy got pulled by another company making android apps before they really took off.
Everyone who got the CS degree has done well honestly. But the ones that went to google never really stuck around.
At the end of the day, its just a job just like anything else.