my 2 cents, as a recent HANS user: when I hit the tire wall sideways on the uphill, the HANS limited the sideways movement of my melon, eliminating any neck injury...HOWEVER, the HANS did provide a heightened level of excitement and training in my qualifying session and 2 races, as the harnesses slipped off midway through the sessions (what's that sliding down my arm????
) just an excuse to drive smotthly and consistently! MJA, your S&M device surely can't offer such an advantage!