How worried are you about the weight of the aerohead? That is what I use and love it. I have yet to get more than 130km done in it but have not noticed its weight at all (I know others have mentioned it). I am a bigger guy so maybe not as relevant. Surely just doing your long rides in it will help strengthen those muscles anyway so it is not an issue?
I use the Giro Vanquish as well and if I am really worried about ventilation for only a slight aero penalty, then the new Evade is pretty slick.
Edit: PS-hate the boost. Brought one and sits here never being used, does not suit my head shape, when they go on sale for ridiculous prices you have to wonder if the market is speaking....