People who use these, do you use them all the time or only on particular surfaces? Do you do some runs in heavier shoes (and if so, why?). What have been the advantages to you of using them? And (silly question coming up), are you meant to wear them barefoot i.e. no socks? I like my current running shoes and they are much lighter than trainers, but I wouldn't mind something lighter weight to run in. Someone mentioned merell gloves on another thread and I like merrel's normal trainers as they tend to fit me very well, so thought I might try some, but to be honest I don't really know that much about it.