ok here what i've seen in two days observing the AI's colonizing planets:they are getting 100 milions peoples on planets 19 class and up,and 200-250 milions on planets 15-18 class.that seems to balance their income in the early game so the planets lower in class have as much income as those high class planets.and the population increases at almost the same pace so later in the game the population on the planets won't be so unbalanced.i hope this helpes.
What's the net result of this strategy on the morale of the planets?
My concern is mostly morale, so I'd rather have all planets with the same morale. Putting lots of pop on a PQ15 to have it produce money is not good IMHO since that'd just lower my morale on the planet and the pop would probably produce the same money if it was sent on a PQ19, while keeping good morale.
that i don't know but the AI's don't seem to have our problems with morale.i tried to do that and it worked just fine with the morale but i kept taxes at default(33%).of course morale was high much longer on better planets but when it started to go down the toilet i built entertainment network.later in the game i built teleporters.that works for me-i'm playing challenging now