Different agencies have different ways of doing things PageTurner.
With the one I am looking at you interview various carers by phone and skype (as it is a national agency) and then choose one to come on a week's trial. If it works out, then they stay for 4 weeks and then have a week off while the agency send a sub for that week. Then the primary carer returns, and so on.
The carer is entitled to 2 hours free time during daylight hours each day.
The cost is on a par with nursing home or residential home care.
Lots to think about as it would be a huge life change. The loss of privacy would be the biggest factor; but there would be several gains: consistency of care (at the moment a team of about 8 are bobbing in and out, and they all do stuff differently), flexibility of care (currently he has to have the care at the times booked which means he has to get up/go to bed/go to loo according to the schedule rather than when he wants to), and it would also mean I could leave the house for social and other activities without having to book extra care in advance.
There is a lot to think about.