The secret is Skeinforge!
So far I had steered clear of Skeinforge because it seemed quite advanced and complicated, but my general aim today was to improve the print resolution, and my particular goal is to print a replacement Mendel pulley. These are sufficiently intricate, and also small enough to print quickly. The difference between the results yielded from the repsnapper gcode generator and Skeinforge is pretty big, which comes as no great surprise really, and I was pretty happy with the results.
The two videos from Prusa helped get me started working with the tools, and his initial Skeinforge settings seemed to produce good results. Of course there is still a lot of tweaking to do – but progress has been made!