Mr. Horse
Seriously.
They're fantastic helmets, but they really, really restrict peripheral vision. I loved my RSX, it fit great, loved the helmet, but felt like i was riding through a TV screen.
AFAIK, that's mainly due to ECE22 test procedures vs. Snell. Snell requires a shell that can take two pointed impacts in the same point, on the top, but ECE22 has nine single impacts all over the shell, with I think two on the chin bar.
That means Snell shells are made thicker and heavier, but ECE22 shells have wider chin bars, which means a smaller viewport. Compare Arai & Shoei Snell helmets vs. Shark, Suomy or AGV ECE22 models, and usually the Snells have larger ports.
My RSR2 works fine for me, YMMV.