So UPS was on my block today dropping off my HJC Elbows Spies Carbon Fiber AC-12. It's exactly what I expected since I got a chance to try on my friends Medium size AC-12 that you see signed by Spies himself in the above post. The Medium fit great once it was on my head but putting it on past my ears really hurt. I would expect a slight headache after some time in the Medium so LARGE it is! My Large AC-12 is just the comfortable size to ride in. I wouldn't want to hit those higher speeds with it as it's not that tight but for sport bike cruising speed (which is still pretty quick) it is just the right size.
I went for a short ride around some backroads and on the freeway with the vents open and I can put the noise level of this helmet RIGHT in between the Shark RSI and the Arai RX-7. The Shark RSI is just super silent to the point at which it really surprised me when I first went for a ride in it. The HJC AC-12 bumps the noise level up a notch and a half but also lets a lot more air in than the Shark RSI. Then to the extreme side sits the Arai RX-7 which indeed flows more air through it but in turn produces more sound with the vents that protrude out of the top... and maybe the plastic plates that cover the face shields hinge mechanism.
The AC-12 needs some breaking in before I can comment on the fit but it sits on my head more firmly than the Shark RSI. This can only mean that the HJC AC-12 has more of an interior shape in tune with the Arai RX-7. The material that covers the interior isn't near as luxurious as the RX-7 which is ok since it didn't cost me a fortune. I will rate the interior fabric of the Shark just above the HJC as well. The Shark RSI is one really comfortable helmet when I consider the material inside is more friendly to my face and the front chin bar is closer to my mouth as well. After riding in a Shark you realize just how far the front chin bar is away from your face in other helmets... especially the HJC AC-12. I don't plan on going down on the street anytime soon but I can say that I would rather go down wearing the Shark over the HJC. It feels more substantial just because it fits me a little tighter than the HJC and the chin bar is much closer to my face. I pray I never damage the Arai in any way simply because it would cost a fortune to replace!