Just got mine yesterday (Light Silver). Rode in with it today. Notes:
Stupid light! :teeth Easily as light as RX7-RR4. This is why Arai claims to have lightened the RX-& Corsair. Will compare this to Corsair when we get some Corsairs in.
Finish is better than the Silver RF-800 I had a while back. Deeper gloss and more even metallic. :cool
Fits me like a rubber glove immediately. My Arai always have to 'break in'. I appear to be on the limit of an Arai Large but perfect Shoei Large.
Noise level :shhh - Whistling noise appears to happen when you drop your head too far. Comes off the back of the 'aero' stuff in the back of the X-11. No problem to me. Fantastically quiet otherwise.
Field of vision is much larger than my Arai Quantum/f. I haven't complained about my Arai, just notable difference. Arai claims to have opened it up some on the new RX-7 Corsair, no word on trickle down to Quantum/Astral/Signet lines. :confused
Strap securing mechanism is clip-to-D-ring vs. simple snap on Arai. :mad I prefer the simple snap. Something you shouldn't have to think about to get done, and God help you if you forget it and try to get it while moving and/or with gloves.
By far this is Shoei's best helmet ever, especially for the track where the aero stuff may actually come in to play. Also your head is always up (i.e. no whistling).
I'm happy to have my Quantum/f for street. There's a reason that the Quantum has been consistently awarded 'Best Street Helmet' for years.