If you know in advance that your travel needs require you to check luggage for some reason, what kind of bag do you use to check in? I've been thinking about this lately and if I'm taking something like the Aeronaut on my back, I keep thinking my check in bag needs to be hard plastic and on wheels. At first I was thinking of a nice strong duffle type bag but that could be heavy and I would think it could get jammed on the belts. With a hard plastic bag I have a chance to semi fragile items home if I wrap with clothes. With wheels I don't have to worry about sweating my way through the airport. I suppose I could check an Aeronaut but I'd hate to subjec that to all the dirt and debris of the luggage track.
Just curious what others do when they know they will have to check bags.