from my testing of the night brake, it did not seem to affect accuracy at all. The only difference I noted was massive reduction in recoil over a muzzle nut. With winchester ammo flash was reduced as well, but with wolf I noticed no difference in flash. The recoil reduction was not noticably different from the Czech style brake I went back and forth and could not tell the difference. I would rate them as equal, and would recommend the one that you find more aesthetically pleasing. The night brake is a little bit lighter, but barely noticable.
I would rally like to see some third party reviews, but have received very little feedback on them, all of it is positive, but none has been detailed.