I work from home whereas before I worked in an open plan office. As a developer. I do less hours now at home, but I only work the productive hours. If I'm not 'feeling it' I do something else, I don't have to sit there looking like I'm working, theres no-one watching me and judging me. I don't sit there until I get bored in that state to the extent I'll churn out code with a fuzzy head and so create inefficient inelegant code.

If coding is all you do, I guarantee you're writing bad code.

An hour when I'm in the zone is worth 2 days when Im not. If it takes me a day of taking a break to get into the zone its a net gain.