I've got a couple AGVs in the locker. They are a mid-high line helmet. Good quality. Great graphics. Pain in the ass to change shields. Middle weight. Not quiet not loud. I prefer the Arai over AGV for fit.
I've got an AGV X-Vent. Overall fit is pretty good. Not too noisy. Good venting. It's heavy though, especially compared to Arai. The visor mechanism takes some getting used to when changing shields, but I've got it down to about a minute.
as far as fit and finish between the two, Arai all the way. it cost me almost 2x the AGV so i suppose it isn't a fair comparison.
either way, go try both of them on at a shop. everyone's head is different. i spent an entire day with a friend looking for a helmet with him. he must have tried on about 25 helmets before he found one that fit properly.
I've got an AGV Strada (in black of course). Not very expensive as far as helmets go but I do find it noisy. Probably a result of the vents but its noisy even when I have them closed. Wind noise is so bad I wear ear plugs if I'm doing reasonable distances at highway speeds.
I'll be looking around when I'm in the market again.