[webwright]

I'm not sure I buy your ability to understand your own productivity (people are notoriously bad at that). It's hard to believe that more work doesn't strongly (but certainly imperfectly!) correlate with more output... Up until that work exhausts you to the point and you start doing BAD work. Maybe that # is 35h/week. I suspect it's widely varied based on type of work, type of person, depth of love for the work, diet, exercise, etc.

[kylebragger]

I look at it from a standpoint of what tangible things I need to accomplish, and what I estimate I'll need in terms of time to do them. In the last 3-6 months especially, I've been constantly -under- my estimates. This correlates with starting to work a shorter week, taking more frequent breaks, etc.

Not scientific by any stretch, rather simply my own observations.

And yes - I'm thinking more in terms of folks working insane amounts of hours, at levels that put them well into the "doing bad work & burnt out" realm.