[Vallen Chaos Valiant]

Now, preliminary review of of Psionics...

I decided that there is no benefit in fielding a Psionic Sniper. Squad Sight doesn't work with psionics, and in general a fully upgraded sniper does more damage with regular attacks.

Psionic Heavy might work, especially if she is too far away to hit reliably. Psionic would be a backup weapon when she can't get closer.

Psionic Assult is nice. The problem is that you might want him to shotgun enemies in the face instead. Being such powerful units means it could be better that you use your RunNGun. Okay as a Psionic but only if RunNGun is on cooldown.

Psionic Support is actually the best in my opinion. The use of assault rifles is reasonable but doesn't beat Psionic attacks. So when possible it would definitely be better to use Psionic when in Assult Rifle range. The normal weapon would be reserved only for fighting robots. Their 4 square bonus movement also made it easier to reposition for long rang Psinic assults where rifles have trouble hitting.
(In short, Support makes the best Psi Soldiers because the Rifle is such a mediocre weapon.)