ran it, LOVED it! just did the workout described below yesterday. I went out to a large park and turned my watch on to 4 mins. I ran the 5 x 4 mins. i didn't look at my watch, just repeated my mantra, "it's the effort, 5k effort." I think I did a pretty good job in judging my pace. I felt pretty smashed at the end, but probably could have done one more...just one. I really see how this is going to help my 5k though. I was actually training for a real race, rather than on the track or treadmill. I had ups and downs, corners, and people to get around. I'll probably do this one again in two weeks.
oh, and those Vibram 5 fingers...just BOUGHT THEM! My review will happen in a week or two.