I read the article on a cider yeast comparison project with great interest, as I have been informally testing various yeasts for years. Interesting to see that two of the yeasts produced a reportedly sweet-tasting cider, however, there was no supporting data (final gravity or Brix). I'm left wondering if the yeast really did leave sugar behind - which would be surprising to me - or if there was a flavor perception of sweetness, which I have experienced with some yeasts, even though the cider was actually dry.
Any chance we could see OG, FG, and perhaps pH and titratable acidity? These are basic analytical data that should be gathered for a true research project.