Disclaimer: I know Numbers are not final, these are all assumptions based on the Numbers I saw and I know probably everything will change, please don't kill me Wiz.
Soo... If you took the Synthetic Ascension Path:
Are you still able to grow your pops naturally?
It would be a shame if you had to build every single pop manually.
Changeing your Energy needs in one step also seems more than harmful....
Getting -300 (a SMALL estimate about the Pop-count ~ 360 fan.mat.) Energy over night might kill you until you rebuilt all farms into energy. A period of weakness no other path offers.
(Except maybe bad shroud things, but thats one owns fault for gambling)
Did Robots get an Upgrade?
The boni you get from the Shroud are stupidly high, an instant 10% on top of other boni AND the Shroud as Gamble to get even better Tech (Psi shields usw.)
The Genetic Path allows you to hyperspecialise your pops and gives them the option to exceed synths in any way. (See Industrious + Very Strong)
Even the best two army types (Psi and Gene Warriors) are now locked to those.
What do synths get except beeing synths?
Psi has armies, tech, better FTL, better leaders (having immortal leaders might be useful, but nobody really cares when you can have awesome leaders)
Gene modding has armies, better pops, no weakness the abillity to outperform other pops and grow like rabbits.
Synths get android and robotic armies (I prefered the basic assault armies every time), 100% habitabillity (achievable by preference modding 1 pop once and colonizing, even with psi + some habitabillity tech), 20% every science ( 25%Intelligent + natural x), 20% on minerals (Industrious + Very Strong gives 25%) and 20% on energy (thrifty seems a good alternative)
Synths are the same as before. So why should anyone want to take them?