well guess I can answer that for you.
Roster stability is not very good. I think its mainly due to staffing levels. To be honest BHX just dosn't lose crew but other bases are always recruiting. This means that us Brummies night stop... ALOT
For example I had standby this weekend on Sat and Sun. Checked in on Monday for my 'changed' flight and am now nightstopping in Belfast.
In all honesty I dont blame crewing for the disruption we get. At the end of the day they have to put crew on aircraft and we are definately short in several areas.
As I said stability is an issue and even after checking in for a flight you may not complete the same sectors as planned. Again on Monday I checked in for a double belfast but after the first two sectors we were told that we had to go to scotland. One aircraft went tech and we went to glasgow via edinburgh and back. Were supposed to be finished at about 21:30 but I left the crew room just before 23:00.
Standbys after a duty are common particularly in winter. Usually the BHD/GLA/EDI earlies will have 2 hours airport standby when we land. The good thing is that if the other aircraft are running ok we are allowed to head home instead of sitting in the terminal.
How much do we fly? Well Feb's roster came out and I had one nightstop in Jersey but so far have also stayed in Edinburgh for 2 nights and have Belfast this weekend. This month I am doing 61 sectors which is fairly average. We work different patterns. Usually 5 on 2 off but you will also get at least one 6 - 3 and occasionally you will do 4 - 1 - 4 which is a bit tiring but that happens very rarely.
Now it may not sound great but what with you loveley BA people coming over we have been assured that stability will improve for all crew. Also as you say there is a new scheduling agreement coming up which we haven't seen yet but are promised is better than current conditions.
This may not answer everything but if anyone has any more questions then just ask!