I've shot it. Recoil is low, muzzle climbs is minimal, accuracy is good. Grip and sights were average. I just shot a buddy's 5x at dirt clods in my pasture so no real review.
Another caliber just means another case of ammo that i gotta buy and store. I got enough now. I'm gonna wait for phasers.
Went to go see if the dark mountain arms single shot 5.7 ever got made. They did. Also saw several other 5.7x28 pistols and rifles I'd never heard about.