I've worked in three separate Google offices, and never saw someone use a nap pod once. I tend to vary my task depending on the time of day an my energy level, e.g. code in the morning, review other people's CL's and do boring non-coding tasks in the afternoon. I think the focus on napping is more part of HN echo chamber (wish there was a less pejorative word, but it's a real thing) than something most people want to do, since Googlers have every opportunity and never do so.