All our crews on the Challenger 604 and Global Express are trained for CAT II.
In Canada, if privately flown, all you need is an annual training with CAT II and a PPC/IFR test every two years.
If you fly commercially (as in charters) you need to do annual training and do a PPC/IFR ride too.
As for maintenance with these new aircrafts with digital avionics it is a lot simpler and much less expensive to keep the aircraft CAT II certified. I'm told that instead of an annual inspection for certain avionics, we now have to do it bi-annually and the cost to the owner is peanuts.
Our Ops manual says we have to do an actual or simulated CAT II (by shooting an approach to CAT II limits on any ILS) once every 3 months.
In the last 2 years, I have had to delay substantially (5-6 hours) or cancel four flights while in Europe that if we had the CAT II approval would have gone on schedule.
Some crews have also been able to take advantage of our CAT II ops in wintery conditions here in Canada.