It's not as black and white as that for me, but that definitely does happen.
I find working from home 2 out of 5 days to be great for my productivity, while still being very available to colleagues.
Weekend hours without anyone else in the office is generally 2-3x (as measured in a BPM database) as productive for me.
Interesting, I would say depends highly on what you are doing, and how self motivated you are. With certain tasks, I feel a day in the office is as productive as a week from home. I also found it weird that everyone jumped on the efficiency bandwagon. I actually know people who work from home, and there are definitely a sufficient number of them who do very little productive work in a given day (not that it is necessarily different in an office).
As long as you don't have to respond to email, chats, calls or other questions and don't have to talk to anyone at the office.