The pay was great--and even better when the pager bonus (which was not mentioned in the offer) is counted.
The tech is, as it must be, groundbreaking. There are more problems with tech debt than might be expected, but resources tend to be thrown at problems before things go critical. Do note: on average, the engineers there are merely above average. Lots of greatness there, but also a lot of embarrassing code.
Their promotion of tech leaders to management has a siginficant drawback, in that these two skills are extremely different. First-level managers especially are very random in their skill.
But beware: Google is even more aggressively liberal internally than externally. Conservatives keep their heads down, and being outed can lead to unbearable conditions.