Hi Sapphire,
I know alot of runners that use the new five fingers or minimalist shoes. They have all said that the change is significant when you run in them. They said because they were wearing running shoes with lots of cushioning and support for so long, that once they started running in the minimalist shoes, they had to in essance relearn to run. The muscles in their feet were not strong enough to do the running and had to run slowly to build them. Most people said after the first run, their feet hurt something awful, but eventually got better after a few weeks of running in them.