Ok, so this is nice big new addition to GalCiv and overall I like it a lot. It slows down the colony rush and encourages you to build a more well balaced civ from the start. If you don't invest in any colonization tech, you'll be out colonized. Invest in too much, and you'll fall behind in other areas. There is just a bit too much randomness to it right now. I did a lot of Ctrl+U and Ctrl+N trying to get a feel for how map generation changed as I tweaked settings. It seemed to be a complete krap shoot when it came to determining which worlds required extreme colonization tech, and where they were located.
That said, I have some suggestions.
1.) Galaxy setup screen should have a selector for the percent of habitable planets that require extreme colonization tech (Rare, Uncommon, Abundant, etc..) just like the other features. So on the one side you could have a galaxy where the technology is rarely needed (more DL like.) On the other end, there are very few "Earth like" planets in the galaxy. The cost of the tech would scale accordingly, so in a game where extreme colonization is rarely needed, reduce the cost. On the flip side, you would raise the cost when most of galaxy requires some form of extreme colonization, as each new type of colonization tech would open up large parts of the galaxy to you.
2.) The quality of the planets should be better tied to the tech required to colonize it. It seems rather silly to fly into a new system to find this Class 19 "Earth like" world sitting next to a Class 4 Aquatic world. Unless I have no other choice, why would I spend months researching the tech to colonize it? Those Class 26 planets you find around purple stars should ALWAYS require a colonization tech.
3.) Super Adaptors should simply have the research time for their first two colonization techs reduced to 1 week. That way they can pick the techs that best suit the current game. Being able to colonize Barren worlds isn't much good to me if the nearest one is half way across the galaxy.
Thoughts, opinions, comments?