The fundamentals are solid (the line height is perfectly alright, about one hundred characters per line are within the range of empirical results on optimal readability).
I suspect the font is so small because the design is so old. As far as I know it hasn’t been updated in ages. It’s old but by no means bad design.
Ethan, the author of the RWD article, was actually on the team who worked on The Boston Globe site. He's been giving talks on the project and the process. I don't know if it is anywhere online, but it's very interesting.
This looks like a good start to get the basic idea with examples on this space.
Today is the first time i saw something like this and im really interested on learning it.