S2 and C3 Pro are two different types, FF vs Modular, respectively.
When I sport ride on my Ducati, I always wear my Arai Profile FF helmet. A FF offers better protection due to the nature of its construction.
When I tour, I use my Schuberth C3 Pro. It is the quietest, best made, modular helmet I have ever used, and I have used Shoei Neotech and Nolan N104, which are also both great helmets. I like the convenience of a modular for gassing up, glasses, photos, drinking, talking, whatever. All have great features, but the one thing I love the most about the C3 Pro is the ratchet chin strap; Nolan has that too.
Don't know anything about Klock Works, but I am 5'9" and a Freedom 11" touring shield is almost perfect for me wearing an open face helmet. A 11" or 12" should be good for you, depending on your seat. Call Freedom, they will hook you up and let you try whatever shield they send you. Excellent products and service.
John, Medina, TN - 2003 Honda ST1300 ABS, 2011 Kawasaki KLR 650, 2012 Ducati Monster 1100 EVO
2017 HD Road Glide Special