Not to disagree with your general direction though, but i don't honestly think i could boil what i do down into 2 hours. On paper? possibly. In practice i spend far more time thinking about problems, taking breaks from problems, etc - than i do actually writing the solutions. But i'm not claiming i'm any good heh, just that it often takes me hours and hours.
Your assertion is generally correct i think in efficiency sake. Ie when i put in 14h days, i'm exponentially paying a higher tax on my efficiency by putting in extra hours - i'm over worked and tired, i'm far from my best. But i still think i can more work done in those 14h than i do in 8, or especially 4/etc.