IMO one advantage of the more expensive helmets is better fit. The cheaper helmets typically seem to come in "one size fits nobody well" sizing while the higher end helmets come in 3 or 4 sizes and have internal adjustment as well. I want minimum clearance inside a helmet so that my head moves the least possible before contacting the shell in an accident.

I agree that if the helmet is tilting back on the head then the front straps are not adjusted correctly. All helmets I have owned have had provisions for adjustment of the straps to get the correct angle on the head.

Wind noise varies from helmet model to model and seems to be related to the vent design.