Okay. Voted Exo-Waves and None of the Above.
I voted None of the above because I look at a lot of the things on the list and go "Yes, that unit annoys me, but I don't consider it OP".
Note this should be taken as 'abstain' on the Champion stuff as I don't play with that on and so can't comment on it.
On exo-waves however, the new starships need to cost the AI more I believe. Their DPS is lower (relatively) but their high-health means they just don't die!
When they have a specific target, such as when part of an exo-wave, that survivability makes them a lot more dangerous then they are in general gameplay.
I also think exo-waves need to be re-worked somehow so that a choke-point is not required to defend against them, but I don't want to just nerf their numbers as their current balance is about right for when you do have a chokepoint. This probably needs its own dedicated thread before anything is done in this direction though, it is a pretty massive change.
I did not vote for gravity units (the current frontrunner) because these fall into the "annoying, but not OP category" for me. Especially now that you can unlock Spire SS which are gravity immune if you are fighting a Gravity Driller AI or something.
Abstain on the Ravenous Shadow (2nd place atm), never played that scenario.
Warp Counterattack (3rd place atm): Did not vote for this because this is basically the AI's only mechanic to get around your defensive chokepoint and is on a 15 minute timer. Does this slow things down while you deal with it? Yes, but I am of the opinion that the AI should be able to get around your defensive chokepoint and I'm actually of the opinion it should have more ways to do so.