If you ride in the Olympics, I'd bet your helmets would be sponsored and you'd wear what they gave you.

Until then .... if you are finishing second by a few seconds in race after race, go more aero. otherwise, get more fit.

If you have too much money buy five or six helmets and do a lot of back-to-back tests.

Otherwise, I wouldn't worry about the .05 aero improvement of anything but a TT helmet .... and when you really are high up in the ranks of Triathletes you will be hanging with top-tier triathletes who will likely know the best helmets and the best prices.

As far as I know, aero position on the bike is what really matters ... that is where the greatest gains and losses happen.

Also ... heat prostration tends to have s lowing effect ... before you pass out. Comfort can help you go faster.

TL;DR: I have no clue but I like to type things.