I'm waiting to hear back from Apex on this. I will post it when I hear back (probably on Monday).
In the meantime, feel free to post your own comparisons!
I've heard back from Apex, and according to his email:
They all have a different profile. Xerxes is high androstenone with supporting ingredients designed for enhanced sexuality and dominance.
TUSC is high androsterone with supporting ingredients designed for high status and public elevation.
Titan is high in both androstenone and androsterone but has a strong social buffer the other 2 don't have. It is a middle ground of Xerxes, TUSC and a strong social.
TUSC and Orbital will come close to creating the Titan signature. 2:2
I have a bottle of TUSC someone gave me but haven't used it yet. Thanks for the background on these mixes.