I once heard it said that employee overtime was like morphine for employers, because it masks the pain of organizational dysfunction. It's important to let your employer feel that pain so that they can become aware of what is wrong and fix it.
One of my jobs in Germany had a strict 35 hour week. No overtime allowed unless paid 2x and even that was very difficult to do. Management was definitely much more decisive and we worked most of the 35 hours. With my current employer I am pretty sure I am working less productive hours but I am in the office more. Meetings, meetings, conference calls, more meetings and no clear decisions.
Unless you're hourly.
Saw this in Oil and Gas industry among Engineers and Designers (the pipeline/wiring kind, not the UX kind), not sure if it's true for other industries though. Haven't worked contract in software yet to see for myself.
Until of course the brown envelopes came out then as he said even the tea boy got a grand - this is mid 70's btw.
I'm starting to see it as a loss, the additional time I may put in as overtime is subtracted from time I have for side projects and learning that is far more important to my career (as well as metal / physical health).