i think i said this just yesterday, but for the sake of repeating myself...
the bell slant (40-50 bucks) and bell citi (25-30? bucks) were the two top-scoring helmets for adults in consumer reports' bike helmet tests. i have the slant and i wouldn't pay more for a helmet now that i know this one is available. it has lots of vents, it looks nice, it's highly adjustable. mine was $40 at performance bike.

ps: i have a kind-of big head, too, and this helmet fits me very well. i don't know about small-headers, but i'd guess it'd work for them too! you can try them on at performance bike if there's one near you.