Historically, Giro helmets fit me well, but this one always rotates on my skull such that the brow piece encroaches on my eye, forcing constant readjustments. This is because of the shape of the lower rear part of the helmet cutting in more aggressively than my head shape allows. It just doesn't fit my head correctly.
I came from a Giro E2 which was lighter and much cooler. It's still winter in Santa Cruz, but my head is cooking every ride. Another thing I've noticed with fewer vents is that it's much harder to scratch my head. For colder climates, and different shaped heads, it's probably a great choice, but I need to get something else.