are there any drawbacks to keeping Synthetics enslaved?

So I've finally have Synthetics and my own civilization is heading towards the Synthetic Evolution ^*. As a materialistic empire I could give regular AI citizen rights. But why should I bother?

Yes, there is a risk of AI rebellion, but IMO it is less dangerous than something like the Scourge invasion, and the effects of Slave Processing Plant and Share the Burden edicts can greatly increase their production output, that otherwise I'd have to control by managing egalitarian faction happiness. So it seems that keeping them as slaves is MUCH better solution, or am I missing something?

In other words, is it better to keep AI as slaves or give them "human" rights (assuming that I am not worried about the rebellion).

^{* which, with the recent patch invalidates the question - once you upload your brain into synthetic body, pre-existing Synthetics join your population on equal rights}

Solution 1:

Note that enslaving AI is only when they've become synthetics, not droids as they are not sentient enough at that point.

So there are some drawbacks that could occur when granting rights to your AI population. Beyond the rebellion that's possible if you progress the advanced AI tree enough and actually trigger the rebellion. It is possible to grant rights and not have the rebellion trigger. (Reminder that opponents could trigger this rebellion and it has a chance to spread to your or other civilizations).

So, drawbacks for granting AI rights include:

• Anti AI (non materialist) pops in your civilization may dislike it and become unhappy. This can lead to other issues among your empire and make factions complain further.
• New factions can develop, and existing ones can become unhappy (could be happy depending on your ethics etc)
• Spiritualists hate AI and every little thing you do for them such as rights, allowing them to lead and so on. Whether this is opponents in the game or pops in your own civilization, they will be unhappy and could lose you alliances etc.
• Giving them rights does not guarantee they will not rise up against you, and it also does not guarantee that they won't ask to join their own faction.

Drawbacks to leaving your AI enslaved:

• Spiritualist pops and empires will remain happy because they hate when AI get rights.
• They may be unhappy just like most other ethos pops will be if the AI get rights.
• You lose out on happiness bonuses for them, which can be significantly better than all the slave bonuses together. In total you can get about +5% more minerals and food while keeping them enslaved, whereas with rights you can get +40-60% (depending on happiness) to ALL yields if you free them.

Notes about AI and granting them rights:

• In order to prevent a revolt entirely you will have to abuse them and get the event chains to prohibit revolts whatsoever.
• For a while, AI revolts have been considered one of the easiest end game crisis, however they've been improved alongside the game with updates.

So in short if I was to give you my opinion and those around the internet, giving them rights seems to be tactically a better option, at the risk of rebellions and disapproving empires/pops.