Spiritualist (Transcendence) or Materialist (Synthetic Evolution)

[Syionic]

Which is better? Spiritualists get tons of benefits (shroud), not to mention the psychic trait buffing research, the possibility of getting the Chosen One, and the powerful Psionic Shields. Materialists can turn into robots and get literally immortal leaders (that rarely break down) along with effective robot pops.

So in total (benefits compared and such) is over-all better?

[Malaficus Shaikan]

From my personal point of view:
Fanatic materialist: 10% research speed be default+ 10% research speed via discovery traditon tree. 10% research speed from Technological Ascendancy + 10% from research grand edic's.
That is 40% research speed just for existing.
It is very commen i got 80% research speed when playing Fanatic materalist.

Fanatic materalist are to my knowledge the fastest tech rushers in stellaris.

Spiritualist?
Lets pray to the random dice gods for something good.
Anyone who ever prayed to the random dice gods know how much of a fickle bunch they are.

The simply truth is:
Psionic's are for fun.
Robots are for winning.

If you want to win: Rogue servitor, driven assimilator or devouring swarm.
If you want to win as normal empire: Fanatic materalist xenophile technocracy mechenist.
Why?
Because 40% increase research speed. Robots can be specilized into mining, farming and later amelmities gathering.
Robots have more health and no morals in there armies.
And to top it all off:
Synth's get all the advantage's of robots with the added bonus of happyness.
You need to be extreemly lucky for the shroud to give you anything that puts you on par with a Synthetic evolution empire.
All shrouds advantage's are temperory and come with a cost.
Synnthetic evolution is just a plain upgrade.

Granted The strongest accesion is genetic modifcation.
Psionic's and Synth's only enhance.
Genetic modifiction allow you to create the perfect spieces(or as i learn on the internet: Create the worst spieces then kick them out of your empire so all those goody two shoes empire's suffer under mass worthless immigrants)

[Othobrithol]

I'd agree with most of the above as far as who has the most potential but psionics has the advantage of being much quicker to tech into (and even has one or two events that lead straight into it).
Even beyond that, there are some subtleties worth mentioning.

Both +10% research from discovery and Tech Ascendancy are available to both paths so we'll set that aside.

Materialist->Snthetics gets +% research passives and edicts, but Spiritual->Psionics gets +% unity passives and edicts. Which you like better is up to you, but they are pretty equal imho. Tech is more useful moment to moment but unity unlocks traditions and perks. Regardless of ethics, most of my games I'm well into repeated techs before I unlock all my perks.

Although we really shouldn't even count ethics bonuses, anyway.

Not to mention that as a leader trait, Psychic is way better than Synthetic.

But yes, the shroud just plain sucks. They need to replace all those horrible temp buffs with giving a rival a temp malus (with the slight chance of backfire). Then the shroud would be useful.