I've enjoyed this discussion so I'll throw in my 2 cents.
I intend this only as another anecdotal evidence and I don't wish to impose my beliefs on anyone I simply wish to share what I have learned.
I was skeptical of minimalism at first however over the course of time I continually found through much trial and injury that the lightest shoes worked best for longer distances.
I was a heel striker but forced myself to become a forefoot striker...end result injury. (2003) (After that I could go back and forth without injury)
Ran in Elite version 1 and 2 until version 3 caused severe pain in both Achilles tendons. They added slightly more to the shoe... Switched to air structure triax version whatever my memory isn't that great. After that I started having some PF problems in one foot. (2005)
The trainer said "get Orthotics" I responded "Hell No". Not that I had anything against orthotics but ever single person they treated was continuously injured. They told me don't run barefoot. So what did I do? I ran barefoot workouts...the best of my life on a grass track...PF was cured after a month and 4-6 barefoot workouts. Did barefoot workouts cure it? I believe so but cannot prove it.
2008 ran 2:36 marathon
In 2009 I developed much more severe PF (both feet this time) with no grass track to workout on anymore. I was in pain ever single morning and in pain the first mile of each run. I'm 24 with a running streak since Jan of 2005. Tried strassburg sock...mild relief..still in a lot of pain. Ordered a pair of five fingers kso... after 1 month of a few recovery 3-4 milers in them weekly, PF was 95% gone.
Side note: other unexpected benefits of five fingers is that my Achilles tendon that has been sore/stiff for 6 years feels 90% better.
Still don't know if I could train in five fingers at high mileage because I had a groin injury partly from running in normal shoes and partly from a drinking incident...yeah don't ask its just now to the point where I can run more than a few miles.
I plan on doing two marathons in them the second being Boston just to find out how fast I can go in them. If it works great if not at least I know how to cure Plantar Fasciitis.
Give it another 2 years and I'll let yall know how the experiment goes.