Continuing on from previous thoughts on golems-in-war. Probably worth noting a thing that could dispatch a golem is another, better one. Or two golems. Yeah, that'd do it.
Of course, the military applications of golems is only one use. When used in industry, the widespread effect will be far more pronounced, as can be seen by the development of similar systems in actual history - the inventions of the Industrial Revolution are a good roadmap, as is the modern computerisation of many processes. A long-term investment which enables more work, faster with greater efficiency all round - no upkeep, no requirement for sleep or indeed living quarters. A well-constructed golem, though probably wildly expensive, can indeed pay for itself.
Of course, many of the negative impacts of both the industrial revolution and the modernisation of industry are inherent in golem-labour too - widespread loss of jobs for the working classes, who have been replaced. Societies using golem-labour could not simply train some of these people as operators or repairmen - as inherently magical creations, the average folk would be unable to interact with the golems in any meaningful way. This leads to widespread unemployment and dissatisfaction, a dangerous thing in a more primitive, feudal society.
Potential coping mechanisms could include the development or expansion of a permanent military force, probably equipped with arms and armour made of golem-mined ores. A well-equipped permanent army will compound the economic advantage this society has over its neighbours, and would allow significant military success - not only are the armies larger and better equipped, the men are soldiers by profession and are not needed back home to till the fields and work the mines. This is in addition to the use of golems in war, nearly assured in a society which utilizes them to the degree that a significant number of people are out of work.
In addition to this, the use of golems within industry allows for new forms of product to be created and sold - golems cannot drown, and could well be capable of extended underwater operations. Furthermore, although slow, the inherent ability to bear incredible weight and move tirelessly throughout the night makes them effective pack animals for all manner of journeys, in addition to doubling as intimidating guards.