bmlb said:
Do you attribute the Korean "half-decent condition" to their being scientific? If so, I have to agree with you.
(Repeats credentials ... 'average' Emperor player, no Sid-level zen master! Happy to be corrected by a Sid-level zen master.)
I think that the 'scientific' trait pretty well infers that you're doing your own science to at least part keep up with the AI, rather than relying almost entirely on trading or demanding techs through the game. As a scientific empire, you will probably research the rarer aspects of the tree and line up trades for the rest.
While I'm no devoted advocate of the scientific trait, its cheap libraries can help with culture flips, and it's a handy trait for cultural victories. The free techs at the start of each era are a good plus, but at higher levels it's less likely that you'll be a technology leader, and you'll often just pick up techs that most other civs will already have, so it's of limited trading value - albeit at least you'll be trading at a more advanced level of the tree. The improved chance of picking up a great scientific leader is nice, but I wouldn't think that it warrants selecting the trait over some others. I think the higher the difficulty level, the less potent this trait becomes.
The 'commercial' trait lifts the optimum city number by one-quarter to one-half (as I read it, contingent on difficulty) thereby acting to counter the extent of corruption and waste in larger empires. Extra production shields and science / cash / luxury help with managing medium to larger empires, especially those with a sound infrastructure base where improvements such as marketplaces have a multiplier effect.
It was as much if not more so the 'commercial' aspect of the Civ, plus the lethal bombard and the possibly late but not absolutely horrendously late golden age (just before Cavalry) that I thought put the Koreans in a reasonable position for expansion from then on.
By a 'half decent' position, I was envisaging a Civ that had good access to key resources and some luxuries, 'say' 30-ish fairly well developed cities on a standard or large map, not too far behind in tech', generally a reasonable military, probably sitting in The Republic for much of the game, at least an OK reputation, and so on. Maybe sitting third or fourth in terms of score.
With a good infrastructure developed with a commercial focus, the human player is increasingly in a position to begin to exploit the weaknesses of the AI as the game progresses from the late Middle Ages. Stacks of doom, bombardment, initiating dog piles, wonder pre-builds, and so forth can be more effectivly engineered with more advantageous outcomes in the latter part of the game than earlier on, where arguably the AI's advantages are more pronounced at the start.
With the opportunity to be closing in on tech parity with the top AI Civs and Communism in the not-too-distant future, Korea with its UU, free Industrial Age tech' not far away, likely Golden Age (if not already triggered), and 'commercial' trait bonuses can set itself to strike a blow in the Industrial Age provided that it's established a competitive position to that point.
Admittedly the Americans' 'industrious' trait is great when railroads kick in, as faster workers building railroads allow for all of the bonuses that stem from railroaded tiles to be delivered back to the empire, but also vastly improved mobility when waging war.
So I guess I'm saying that the Koreans' punch tends to be focussed more in the late Middle Ages and early Industrial Age, and can expand from there. Conversely, the Americans, despite their Modern Age UU, tend to have a strong start to the game in the Ancient Age with their 'expansionist' trait playing a significant role, added with the 'industrious' bonus shields and fast road connections and mining / irrigation working to establish a sound and ideally large base.
As a player who tends to wage wars in the later game, it occured to me that the Koreans' traits may have suited your style to some extent.