NFH,
From the 777 point of view; 75-90 hours/month on the Boeing 2 crew without a bunk is not unusual and equally knackering.
Uplink
The contract, whilst black and white in print, is still open to interpretation and of course this flex is 100% in the favour of the company. We have NO input mainly due to the fact that the guys who should be representing our point of view higher up the food chain don't.
You can reach 900 hours in a myriad of ways. EKs argument is invariably that it is 'legal', ours is that it is often impractical and unsafe. As Mr Ree said, if you run so close to these limits things will break.