The Streakfly is the short-distance racer. Nike built it on a track spike's last with a 4 mm offset, which puts you onto your forefoot, and at roughly 145 g it is the lightest road shoe in the range. It is for the mile through the 10K, and for track sessions where you want a racing feel without spikes.
It is low and it is firm. There is a carbon plate but not much foam beneath it, so your legs absorb more of each stride than they would in a marathon racer.
It is not a marathon shoe and not a trainer. Past 10K you will want the extra stack, and daily miles in it will beat your calves up.