I've been out of the game for 5 or 6 months cuz I was bingeing on Imperator Rome, so now I'm like...
So with the combined pop growth mechanics and the way that habitability currently works, is the general wisdom still "Colonize everything nmw cuz pops rule everything," or is it better to be picky?
My hope is that this will be less of a thread of "here are 100 pages of ALL the maths," and more of a summary of what you learned from those maths and your experience thus far.
It's still useful to colonize everything. The new question is- is it better meta to take rapid breeders, or adaptive?
My money is that, over time, 'ALL the maths' would side on Adaptive. While rapid breeders still has the net 5% growth rate vis-a-vis the growth penalty mitigation of adaptive, the post 3.0 changes to pop growth mean that you get a significantly higher growth boost from other growth mechanics. A (net) 5% growth boost on the old base 3 growth is +0.15 growth per month over just adaptive, but the new capacity/housing growth bonus can be +1.5 to your base growth before the modifiers (ie, from 3 to 4.5 base growth). Add in breeder worlds, where you let new pops grow and then auto-migrate in your empire, and the old pop growth factor of rapid breeders is dwarfed by other mechanics.
At which point, it's just a trade off of how much benefit you get for how long. Rapid Breeders is only useful for the pop that's growing while it's growing, but it does nothing for pops already born and it's completely obsolete for better biome species, where 20% habitability advantage is 10% growth already. Whereas habitability is a 5% growth boon in the growth phase,
and a 5% job output bonus even when other species are the ones growing. It can go obsolete in the time until you get 100% habitability through special worlds, tech, and terraforming, but that's to say the first- and most decisive- century of the game. At which point, how many more pops are you expecting to get from Rapid Breeders in the opening decades, and will they make up the pop output difference for the first century?