I have owned many helmets throughout my riding career starting off with(in chronological order) HJC, Shoei RF-1000 diabolic, Arai RX-Q, Arai Signet Q and now my new ShoeiRF1200 Phantasm. I have to say I don't if if it is the shape of my head but this is by far the best fitting helmet I have ever owned. I have plenty of room in the mouth/nose area unlike the Arai. It also leaves room for glasses if you happen to wear them or you want to leave the visor up and ride with sunglasses.
My measurements came in exactly at the very top end of a size medium so I that is what I ordered. It fits perfectly snug around my crown and the cheek pads are slightly tight but remember that the helmet will break in 8-10%. I love the graphics on the helmet as they look much better in person than they do in the video or in a picture. I love the pinlock idea because I cannot stand when a visor fogs up whilst riding.
In any case I not only have I owned a few helmets I tried on almost all the new models out there before making the decision and this was definitely the one.
I just traded in my 2011 Triumph speed Triple Se for the new Aprilia Tuono V4R ABS in white an this helmet couldn't be more a match. Shoei really out did themselves on this one!