Carguard, in terms of overnights I think it just depends on your base. I'm in Sydney and in the just under two months I've been flying I've had approx 22 overnights, with only 1 day trip. This means a good portion of my pay cheque has been tax free.
From my understanding, Sydney base can often get a lot more overnights than other bases, and it varies from roster to roster. Minimum rest on a layover for me has been 12 hours. The longest I've had was 28 hours (which was before the red eye back to Sydney).