I'd agree on the use of serif, but not on the majority of researchers reading research papers on actual paper. Even on screen (and esp. on a good e-reader), I'm still more used to reading serif fonts in research papers.
I bought a cheap Brother black-and-white two-sided laser printer in college, along with a high-capacity toner cartridge. Use a high-quality stapler to put 3 staples along the left margin. I have printed many thousands of pages of articles. I can't recommend this highly enough.
I finally got my hands on some decent e-ink readers (the HD Kobos, when they still had a micro sdcard slot), and it's pretty pleasant to read papers (particularly in natural/external light) using KOreader[0], without having to deal with physically printing them out.