Ok, I think I've found good values for the homeworld research:
Cultural Center research multiplier x 10
Cultural Center research generation 1000 (x 10)
This gives a starting research base of 21000.
If half the remaining (medium) homeworld slots are devoted to research Megacomplex III's, this gives a research generation of about 61000. If you fill the HW with research megaplex III's, the generation base reaches about 107,000, but of course at a huge cost in resources and lost income.
This potential is offset by reduced trade value compared to 2.5 (20% -> 10%), the resource sacrifice, the increased research costs in 3.0, and now, tweaked research and construction costs for the megaplexes.
My impression is this is about right. Let me know if this seems off to anyone.
I'm not so certain what to do about the mineral generation. My inclination is to leave it at 30x, or maybe drop it to 20-25x. At 30x, you start at about 45-50K mins, and can increase that eventually to about 200K without concentrating homeworld slots, or go up to about 500K if you dump everything else and fill up on Min Mine Megaplex III's.
Seems ok to me. But again, if this seems off, speak now.
I am thinking though that these multipliers will mean we don't need to double the resource values of planets, as we'd discussed earlier in this thread.
PvK