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The article attributes quite a bit to this nifty little device, but you have to be realistic, you can make the same claims for paper and pencil (a table of logs can be calculated as a series expansion to any desired accuracy). It's just a convenient graphical method to perform multiplication and division of numerical values accurately over orders of magnitude by adding and subtracting logarithms without having to laboriously consult log tables. It is encumbant on the user however to be familiar with the algebra of logarithms, significant figures, error propagation, and rounding to effectively use one as a replacement for an HP calculator or the above mentioned paper and pencil. Again the gigo principle. They excel at removing the tedium of repetative calculations that are naturally logarithmic in nature like pH or atomic yield calculations, hence the "special purpose models" mentioned in the article.