With 2.2.5 Synth got buffed quite a bit, bio is still the best for slavers, but I can't really come up with scenarios where Psi is a king. Maybe for an uni-specie closed empire like FP of IP? Psi leaders are good, but mechs aren't much worse, and mech pops are generally better.
The only time I really used Psi was as F.Xenophile megacorp, since with influx of xeno and constant interbreeding pop optimization wasn't an option, but still I'd better be off with synths instead.
RP reasons aside, Psi sucks...
The only time I really used Psi was as F.Xenophile megacorp, since with influx of xeno and constant interbreeding pop optimization wasn't an option, but still I'd better be off with synths instead.
RP reasons aside, Psi sucks...