If we are discussing readability of the text set in paragraphs and not headlines or callouts, and not necessarily bothered with the typeface selection:
I think one point that needs to be kept in mind is context of what is being read. If, for instance, I am reading a steamy romance novel or a physical science book I will be deep into the "context" and more than likely will be able to guess what will be the rest of the word. Am I wrong? If a word like "microelectronics" is in the paragraph I assume that the context will lead up to and follow this word. I guess if I were to "choose sides" I'd split it "microelec-tronics".
Just thoughts really. This is interesting.