Gunluvver,
By the way, I have a few myself, LOL.
I found one of the main reasons last night.
With a 28% increase in aluminum, no matter whether by weight or volume, I don't think you could double the amount of current carrying capacity.
But,
According to the website, the CTC cable can be operated under a constant load at twice the temperature of standard ACSC, due to the increase in sag resistance.
So, due to a combination of the two factors, the load carrying capacity is doubled.
Thanks for your post and thoughts though,
Phil