Oh boy, what you said about efficiency in the office is so true.
I spent at least one of my daily eight hours doing nothing because I am there for to long and not in the zone and feel forced. At least two hours are occupied by coworkers asking me stuff and the best moments are when I code very early in the morning or late in the day without interruption.
But it is nothing compared to working at home. I can concentrate for up to ten hours with minimal breaks and dive deep into the most weird code.

Looking forward to go indie one day :)