Rhythmofvision is right: by the time you get Machinery on higher difficulty levels, you'll be facing longbows in cities, and the lack of city raider promotions really hurts the Cho No Ku for that use. They are very effective to ward of stacks of marauding units that are attacking you, however, and Qin does have a nice combo of traits (especially if you can get stone or marble early).
Just completed an Emperor space win with Qin in which I had anticipated using the UU for conquest and had to be satisfied with using them to prevent pillaging. Given the early AI advantage and the industrious/financial push to get early forges, wonders, and cottages built in lieu of a war economy, this is no small consideration.
This in contrast to my previous Monarch domination win with Tokugawa that pushed military matters much earlier. Organized kept the economy from bogging down from city maintenance and the free first strkes of the Samurai effectively double the impact of every strength boosting promotion. That game featured more workshops than cottages, and I built no wonders, though I acquired several...

Just completed an Emperor space win with Qin in which I had anticipated using the UU for conquest and had to be satisfied with using them to prevent pillaging. Given the early AI advantage and the industrious/financial push to get early forges, wonders, and cottages built in lieu of a war economy, this is no small consideration.
This in contrast to my previous Monarch domination win with Tokugawa that pushed military matters much earlier. Organized kept the economy from bogging down from city maintenance and the free first strkes of the Samurai effectively double the impact of every strength boosting promotion. That game featured more workshops than cottages, and I built no wonders, though I acquired several...
