Took a 460 mile jaunt for a free lunch yesterday. I wore the Arai, but took the half shell just in case. Shouldn't have bothered, the Madstad and the Arai worked perfectly together. I had it set 2/3 of the way up, leaned all the way forward. That put the lip of the shield about where the 10" Windvest was.
At 80mph there was no head-toss, no booming, no vibration. There was still wind noise, but that's to be expected. There was enough air flowing over the helmet that the vents were working fine, but not so much that it roared. I had no issue raising the shield of the helmet at speed. It didn't cause turbulence, didn't get any louder, and didn't cause my eyes to water, even without glasses on. I also noticed I didn't have the Sena turned up as much as I usually do.
So yeah, another big win for the Madstad.