I would love my DP to work from 8-5 monday to friday and have 5 weeks off a year!!
I wouldn't have to spend nigh on every evening doing all 'the stuff' while he is chained to his lap top, we'd have quality family time at the weekends and for some of the school holidays. It would be brilliant!!!
And if he was paid for the hours he did, rather than for a fixed number of hours per year, we'd be living like kings 
My DP is very bright, a degree in physics don't you know...and he is no martyr. He's the HoD of a core subject in a large inner city secondary school. As well as worrying about ensuring that kids achieve he's a front line social worker, mental health professional, social engineer....
LooktoWindward - what subject does your DH teach, what sort of school is he in and what responsibilities does he have? 'Cos I bet in his private sector role he wouldn't be expected to develop a large team of staff, teach (and plan) 20 hours a week and carry the can for performance of his dept (against ever changing 'standards') for 40K a year...with no bonus/company car/gym membership/private healthcare. And with the added joy of constant OFSTED scrutiny!!!
I worked in the private sector for a few years and ran a team in an office. Pro rata I was earning shed loads more than my DP for far less responsibility. And once I'd left the office I was 'off duty'.
I now work as a TA in a primary school and can assure you that 20 odd hours of classroom time a week on it's own (without all the planning/marking etc) is mentally, emotionally and physically exhausting. Working in an office was like a holiday. I could wear high heels to an office, and I got a lunch break!!!