I've been training for almost 10 years in racing flats with great success and run 100-140 mpw in prep for marathons. Next year I'm running a road ultra for a club, and they'll pay us to wear Nikes. My problem with most Nike flats is they're too stiff, as I like something with a good bit of flex in the forefoot (like Brooks T7s). I have a pair of Nike Streak XCs, but I think I'd want something more cushioned, without compromising flexibility. Would Nike Frees (3.0s?) be good to try? I tried them on at a Nike outlet, but didn't get to run in them. Other suggestions?