This is pretty much how I feel too.I use ALL the space in my saddle bags when traveling. Even the little bit that the hard liners would take up is too much for me. Most of my clothes go in the tourpack or in a water proof bag on the luggage rack or the seat.
Just as fast popping a few bungy cords to check in.
I would go with the soft liners if I had to choose, but like a few others here, my saddlebags stay pretty much loaded with tools, rain gear, riding gear, first aid kit, quart of oil, etc on long trips.