At any given day, five hours of focused work is much better than eight hours filled with distractions, but I haven't found the magical solution to make that (super-focused work) happen.
Personally, I don't have much of an issue with working hours. The main issue is I can't enjoy long stretches of vacation. Yes, it's possible to sacrifice some of your salary to go wild, but you can't do it without getting a frown from your superiors.