I've had a problem as many have had in the past where even when both planets and habitable planets are set to abundant, their seems to be very few habitable planets.
I've found that when I set Habitable planets at abundant and planets at occasional, I get MANY more habitable planets, and they are often quite nice ones! Even as high as class 13+...
When playing as a custom race with a +10% to planet quality, their home planet starts as an 11, but for me as always had 4 new upgradeable tiles per improvement tech, thus class 23 after Terraforming, doesn't always happen though...
