<< It seems as though NATS management is quite happy to provide pretty bad T&Cs for its employees>>
Things must have changed dramatically, but the amount of time a controller can work is determined by legislation. During my 31 years with NATS and its predecessors I considered the terms extremely good compared to those "enjoyed" by friends in their chosen careers. I had 3 lots of 6-weeks time off over the years in order to visit New Zealand. In 31 years I never worked one Christmas Day, Wedding Anniversary, my birthday or my wife's birthday! I know of very few people who can get more than 2 weeks off at one time. Relatives with "very good jobs" - accountancy, teaching at Public School, etc., simply could not touch my conditions of service. They also worked many hours at home whereas I never took any work home, ever.
A neighbour of ours popped in for coffee one day and the conversation went:
Her: "Oh, Brendan, you're home again"
Me: "Yes, I've worked my 27 hours for this week"
Her: "My husband worked 80 hours last week but, of course, he has a very good job"
Me: "He hasn't got a job; he's living in hell". (That poor man is now seriously disabled after several strokes).
Depends what you want out of life. There are a good few ambition-mad types in NATS who spend every waking hour at work, but they are "management types". OK, they earned much more than me, but I preferred to be at home with my wife.