You have the ventilated aero road helmets that are trying to be more aero than a traditional ventilated road helmet, but not as aero as the next two categories. And finally, you have the new wave of time trail helmets masquerading as aero road helmets (looking at you POC Procen Air) that are debatable whether or not they really should be considered a true road helmet. I would consider something like the KASK Protone Icon or the Ekoï AR14 as a ventilated aero road helmet, and the Aerodinamica a solid aero road helmet.