The highlights of the Song dynasty, as far as I gleaned from this book, were the capitals of the Northern Song and Southern Song, Kaifeng and Hangzhou, respectively. Kuhn describes these two cities in great detail, even naming many family restaurants such as the famous pancake kitchen of the Zhang family, located in one of Kaifeng's 121 wards. It was the first time I really appreciated how great was the potential of Chinese civilization so long ago. You have to wonder what would could have been if Kaifeng had not been overrun after 166 years by the Jurchen and the Mongols took control of Hangzhou, though peacefully.
Sometimes he is a bit sloppy with monetary issues, despite all the fascinating details he provides. For example, on p. 258 he says the money voucher replaced the exchange bill, but doesn't explain the difference between the two, though I might be able to guess. In the next paragraph, he refers to an increase in money vouchers "by 30% to 1,886,340 strings of cash" which later climbed to "an inflationary 5,886,340 strings." But it is very unclear how much of these strings of cash were unbacked by specie. Sometimes he does explicitly make the connection between inflation and unbacked currency but often he doesn't.
There is little true economic analysis beyond descriptions. At the end of chapter 10, Kuhn lists several factors (all in one single paragraph) which he plausibly claims accounted for the outstanding economic performance of the Song: (1) agricultural improvement (2) the concomitant technical improvements in tools (3) necessity of better mining (4) widely available coins fostering the national market. Commercial and proto-industrialization are huge topics which ought to engender far more than analysis. He does not say it, but the paragraph reads as if it were all a very straightforward, linear, and ultimately inevitable process, which of course it isn't.
It's interesting that the famed Chinese entrepreneurial spirit, really coming to the fore in Kaifeng and Hangzhou, did so to a great extent in spite of Confucian rule, based on Kuhn's account. Finally, he does spend quite a bit of time on the influence of Chinese culture on nomads, especially the powerful ones. It is part of the "Confucian Age," which is of course the title of the book, but at least for me, there was too much focus on the non-Chinese groups--the subtitle of the book after all is The Song Transformation of China.
Overall a great reference book which I'll definitely return too.