I think there's something to the head size thing. I'm under the impression that some manufacturers are scaling back to a head closer to 400 cc's due to the wind resistance "issue". I don't have the numbers but it makes some sense.
Personally I can't stand the modern drivers and continue to use a 385cc head size. Monster heads and light shafts produce way too much "downstroke blackout" but all the big equipment manufacturers continue to convince the golfing public that they can provide a bigger sweetspot if you're willing to part with 400 large. When will people realize that a sweetspot is just that.... a spot, and it's NOT the size of a quarter as some advertisements profess.