I'm not an advocate of either style, but I can say that it is pretty hard to change your mechanical habits. Very frequently when people stop and focus on how t

I'm not an advocate of either style, but I can say that it is pretty hard to change your mechanical habits. Very frequently when people stop and focus on how they stand, sit, or move (via martial arts, tai chi, qigong, whatever) they notice that they have built up certain habits which are not really helpful. Slouching, for example, feels relaxing but it's pretty taxing on your lower back... you just don't notice that until later on. Correcting these habits is a pain in the ass... even people who allocate many, many hours can take a long time (years) before they change their natural stance or form. Quick fixes like shoe inserts can even be counter productive as humans are pretty good at adjusting their previous habit to the new circumstance. Because of this, I'm a bit skeptical that changing or removing your footwear 'forces' you to do something right. If you have bad form while running with supportive shoes, I'm pretty confident you'll be able to maintain that bad form while running shoeless.