After a lot of talk about NFs on the board, I thought I'd pass on my findings so far and see if this is typical.
I've had them for 2 1/2 weeks, and used them for all my warm ups & warm downs for sessions (3 sessions a week = 6 runs a week). Each of these 'runs' is 2.5 miles.
I chose to use them for these short runs, cos thats what a Nike rep said they are best used for.
I've found a mixture of things so far:
1) tight calves during warmups, and towards the end of sessions (although this is definately easing)
2)FIRST COUPLE OF REPS ARE ALWAYS SLOWER THAN NORMAL (after warming up in NFs)
3)warm ups are actually slower than in conventional trainers
4)feeling better running on toes though, eg in 400m rep sessions, where this tends go go as I tire as the session goes on.
They're still new to me, but still, these effects all appear quite dramatic.
Have other people experienced the same (esp '2' which is really wierd).
I think they're great by the way.
HR