Lower end Soundsmith cartridges vs others in same price range?

@mijostyn,

If you take the time to wade through this relatively recent article,  "Vibration analysis of stylus instrument for random surface measurement"   http://wrap.warwick.ac.uk/5705/1/WRAP_Liu_vibration_analysis_2010final.pdf, you may conclude that Peter's discussion of tip jitter is correct; the paper calls it tip flight,.   While the article is not specific to a vinyl record, the correlation is unmistakable. The article does present what is the optimum damping ratio as 0.5 to 0.7, and this would then support Peter's claim to the benefit of the lower mass of the MI design; less mass means less work required to damp the mechanism.  

@mijostyn,

The effective mass of the cantilever can not be considered in the same way you would apply effective mass to a simple free-pivot tonearm, and the discussion in this article  http://pspatialaudio.com/analogy.htm#cantilever, highlights that.  The magnet mass and the cartridge suspension have significant impact.  The article models the mechanical components as a electrical model.

Otherwise, you can take what you wish from whatever you read.