My system 6 closes with no problems, single handed.
The only 'issue' I can find is that the visor needs the 'extra' closure on the left hand side - this I find odd.
dealer stated - 'they all do that'
It's by design to allow ventilation apparently
I wonder if there has been a slight red-design then, I have a System 6 that's 3 weeks old and it closes single handedly and seals nice and tight.
I just bought one and mine also seals without any added pressure. I say
seals, but perhaps I should have said
closes, it hasn't rained since, not that I'm complaining, you understand.
One thing that bothers me is the buckle pressing on my adam's apple, it's being pushed back by the chin pad extension, but it is better with the smaller version pad supplied. One other thing I find awkward is that the flip front (not the visor) is so stiff that it's difficult to close single-handedly. Perhaps I can compare mine with others' at Sid's Airhead WeeKend in a few days.
A definite plus for me is the ventilation, my last helmet, a Caberg, did have openable vents but I could never feel the difference between open and closed.

I also like the wide field of view, but with my bike the lower edge of the visor does get in the line of sight when fully open. Anyway, it won't stay open at much over 60mph which I find annoying.
On the plus side, it does look to be very well made- the reliability of its visor remains to be seen, it's only three days old- and to use the cliche, it does appear to ooze quality. Despite the niggles I like it, I think we'll get along fine.