Thanks for that. Yes, the Garmin makes it easy, but I am using a trig which is quite a faff when you've got your hands full of aeroplane and can take maybe 20 seconds to set a squawk. My concern is always that the controller will start to wonder if you have received their transmission while you fiddle with your transponder. But as you say, once the transponder is set, they have much of the information they need, especially if you are near controlled airspace.