I managed to get a couple of pairs of shoe trees in spite of my deepest convictions otherwise. They all managed to fit quite snugly into my shoes with the exception of one. Even though I bought different types (all cedar though) They couldn't quite fit into my Magnannis. The toe end seemed to be under high stress as it has quite a slim profile compared to my other shoes. I completely agree with apropos and RDiaz, cheap generic shoe trees do more harm than good.
As I drove home it suddenly struck me! Why don't I get a well made leather shoe from the thrift shop and conduct a little experiment? Inspired by Gdot and others,I thought I would conduct an experiment wherein I immerse leather soled shoes in water for half an hour or more. Following this, I would tissue dry excess water from both shoes, place a shoe tree in one and leave the other without. I found an Italian made shoe with quite a bit of wear left in it. Soft leather uppers and a more than ample amount of the original sole in place and intact. I don't have the shoe with me now but the name did not ring any bells. The experiment will end either when the sole of the un-treed shoe curls appreciably or the soles completely dry out-which ever comes first. To make everything standard, I will measure the distance from the toe end to the surface on which the shoe will rest in millimetres when the sole is wet/ when is has dried out. I am considering drying them outside away from the sun to speed up the process of drying. Any qualms or shortcomings in the little experiment? Will post pictures up shortly. If there is not difference between the two shoes; I win and I get an extra pair of weekend shoes. If I'm wrong I will be a greater advocate for shoe trees than the world has ever seen