||AFAIK, the claim 'googlers work an average 80h/week' is totally wrong. It may have been true in the startup days though, but including week-ends then.
The googlers I know have wildly different work ethics. Some work regularly from 9:00 to 18:00 every day, some (including myself) have big bursts of productivity like 24h-long coding marathons, followed by some kind of day off..
It really depends on how your team works, and on how you work.
But I know nobody who would be even close to 16h/day. That's just nonsense.
Also, the impression I got at Google is that when people work a lot, it's because they love their project or what they're doing, and not because they are forced to.