I wouldn't call the Aether an aero helmet. A real aero road helmet, like the Specialized Evade can be worth around 10 watts over a traditional road helmet. A full TT helmet would be more, but not very practical for everyday use. As mentioned, your position, and your clothing, are worth more as far as aero goes.
If you're racing, then go for the fastest helmet, if you're just riding, then comfort and fit is the most important thing, and that's a very personal thing, like saddles, just have to see what works for you.