@ N90-EWR: Thanks for the info but your post just reminded me of how things turned out here (Spain). We had a severe staff shortage so our ANSP offered us to make extra time at very generous conditions.
After a few years of that the extra time became mandatory and part of the regular working hours while we were suddenly evil sociopaths robbing from the poor.
I know you guys can't go on strike (neither can we... well, oficially we can but the last time there was a general strike in Spain our dearest government imposed minimum services of 110%

) but if overtime is voluntary I'd be careful with it.
Oh, and we also have as a normal rotation the dreaded 6+2 (usually 2 mornings, 2 afternoons, 2 nights and then the 2 free days... and no, no additional sleeping day).
Look out on that path, c ya in hell