yeah, I think that 100% bonus is huge - I had to build a new city for coal, but even with that delay I could manage to get factories before plastics. for cap, it took 5 turns and for petra city, 3 turns for factory. 25% factory sci bonus alone is not really big (as you already have more than 100% modifier so adding 25% is not that critical), but with building bonus 100% and production bonus it gives and 2 engineer slots are great. I think it's really important to get money for labs, as that's the time when real spt comes in. I think my spt was about 780 before plastics, and it jumped to 1150 with 5 labs bought after 2 turns. for culture.. I think I had couple of culture CS allies couple of friends and that helped. As tommynt said, your cpt should mainly come from CS, not from your own buildings and artists. And I spread my religion to key CS first so that I could get 25% less decay bonus (with patro open, it's 50% less!). I seldom fill any other specialist slots than sci before labs. For some cities with not that many good tiles I put engineer or artist too, but not for main cities. growth is really important.