If it's even 4 | 4, I would always just use mutate on a photon.
It's too unreliable for anything that isn't raw damage.
I'm not waiting until turn four minimum, turn five realistically, to get what could be a useless creature or permanent.
Especially seeing I can just use two cards and get the photon mutate combo out turn 2, or even turn 1 with novas.
Or turn 2/3 with fate eggs.
And upped, SoR fate eggs kinda does blow this out of the water. Really. Turn 5 wins are uncommon but doable.