I've never gotten Extractor AI. I want to try it. I just got Multispiral Architecture for the first time! I've been trying and trying to get this breakthrough. I really like Forever Young, Rapid Sleep, Artificial Muscles & Hull Polarization. Core Metals is one I like to see pop up too. Safe Mode also. It helps a lot from having your pool of colonist reduced if you have a disaster or a chain reaction failure. Right now I'm excited I finally got the Oval Dome!