Ditto on noticing the early surrender...
On a 1v1, Tec vs Tec, normal ai (starting with baby steps before trying a higher ai), Random Small:
After killing the Pirate Base (which was the bottleneck), and crushed 2 of the AI's 7-8 planets, they surrendered.
Met only token resistance post surrender.
(After continuing to play, I noticed a few worlds seemed underdeveloped, while border worlds to the pirates had put up starbases. I like that! It seems as if the ai was making decisions, foregoing developement in exchange for putting up starbases for defense. Other than the intial pirate raids, I successfully bribed them to attack the ai...Maybe the ai learned I kind of liked that decision, rather than placing forts in every Grav well, and/or even at the sacrifice of upgrading, they concentrated on putting bottlenecks at the front lines
Back to topic- I suppose it's hard to find a happy surrender medium to apply to everyone. I certainly didn't like having to locate and crush every insignificant Asteroid.