Here's my recent experience with my Shark RSF2i helmet, which I purchased new last year. I did not wear it until my old Shoei RF1000 gave up the ghost a month ago (the lining fell apart and can't be replaced). Since I started wearing the Shark, the following has happened (in order of occurance):-
-the retaining clip for the end of the chin strap broke off
-the plastic bushing inside the visor hinge 'hole' broke in half
-the lining has started to separate from the foam inner shell around the face opening due to poor glue.
-the breath guard will not stay in place anymore
-the ventilation is almost non-existant, so...
-the visor doesn't "fog up", it literally rains inside
-my head almost boils on a warm day: never had this with the RF1000, even in Osoyoos at 40deg.
-the chin bar sticks out further than the RF1000's, downward vision is severely impaired.
-parts are going to be very, very difficult to find.
-did I mention it's French?
On the positive side:-
-it's a very comfortable fit; that's what made me buy it