The Psionic and Genetic Ascension paths seem very interesting and add a lot of depth and complexity to the game, however the Synthetic Ascension is extremely lackluster in comparison. Unless the robots will have automatic pop growth, additional bonuses that are unique to biologically evolved synthetics, there will be no real reason to play as them. If they're essentially Synths, why not just build synths instead and go down the biological path while you are doing it? This way you get the best of both worlds, as it stands (if using the exact same rules as standard synths, aka no automatic growth and whatnot) it would become more of a bother than a boom to play a robotic empire, I know b/c I have done it.
I mean when you compare the options:
Psionics get access to the shroud, which offers a myriad of bonuses, choice, and player interaction.
Gene modding allows for interesting uses to create super species, and to create subservient ones.
Robots are...robots. No different than old ones, immortal leaders is okay I suppose but not all that interesting either.
If robots had more choices, it would be fine. Perhaps adding in additional portraits so that we can pick to play as different looking robots? Additionally, weakening the overall power of the robots, but instead offering additional traits that are unique to them (and powerful in their own right) that would also double down as additional customization might be what we are looking for here. The portraits bit is probably unlikely, however the additional perks and choices is somewhat reasonable, it could be accomplished in a day by a single person perhaps.
Examples
Robots would only have a +10% yield towards the standard stuff (minerals, research, energy) standard synths would drop in their power accordingly as well, to create a contrast, or these wouldn't be quite like normal synths. Keep the use of food, perhaps they use 'organic matter' to fuel their power cells or something. This way there is a mechanic allowing for them to populate planets without the player getting a headache, take this from someone who used Synths to colonize something like 80 planets in one game, I was glad when the prethoryn scourge wiped me out after they entered in all my core systems, b/c at least then I wouldn't be attempting to click everywhere to produce more synths, which of course my sectors refused to do. Secondly, after the species has completed their transformation, on the same screen where they could alter their name, they would be able to add extra traits to their species, each one would be worth 1 and you would have 2 points. They might include 'Increased Neural Capacities +15% to research yields', 'Preliminary Combat Functionalities +50% army damage', '(insert here) +15% to mineral yields', '(insert here) +15% to energy yields', 'Improved Leadership Matrix leaders gain additional, synthetic exclusive benefits'
This would offer the players more choice, and allow them to create their own, more or less unique Synthetic Species. Including the additional portraits suggested, this would really improve the quality of the Synthetic Ascension. Synths need to either use food, or automatically reproduce (or have that option) so that we don't go crazy with the micromanagement.
Realistically, without the preceding I will still be buying Utopia. However, to note is that unless there is a lot more depth or something similar to what I suggested in regards to the synthetic ascension, there is no chance I would even consider using it. It would become a wasted game mechanic. Other than the synthetic ascension, I like what you guys did with the other two!