I ran with 5+ generations of Nimbus, switched to VFFs a few months ago, don’t think I’ll go back to traditional shoes. I did pick up a pair of NB Minimus Zeros, mainly because of curiosity. I haven’t run with them because of a bruise/injury at the top outer edge of my left foot. It doesn’t hurt with VFFs, but the Minimus are pretty narrow so they hurt like hell right now when I put them on.
After four weeks, Warne remeasured the subjects’ running economy. He found two noteworthy changes: First, the runners had become much more economical in the FiveFingers. While running at the same paces as at the beginning of the study, they were just more than 8% more economical in the FiveFingers than they had been in the same shoes at the beginning of the study.
Second, whereas at the beginning of the study the runners were just a bit more economical in FiveFingers compared to running in the Nimbus, by the end of the study that difference had increased to 6.9%.
via Study: Running Economy Improves After 4 Weeks in Vibram FiveFingers | Runner’s World & Running Times.