I had a brief experience with a Shark RSX helmet. Unfortunately it didn't fit me too well. I'm a round head and the Sharks tend to fit the long oval head type. Nonetheless, it was an impressive piece of work. I'm an Arai fan and if the Shark had fitted me, I would not hesistate changing over to Shark.
Very aerodynamic so it's quieter than most helmet, but you still need earplugs though. But the aerodynamics aspect of it helps your neck from getting too beat up from the wind. Very little buffeting from the wind blast.
Very comfortable. The liner is simply superb.
Awesome ventilation. My head was cool and dry yet I didn't feel the wind going through.
The thick visor also gives an extra degree of comfort just in case a big rock jumps up and hits you in the face, not to mention that it's clearer than anything I've seen.