Found via Quora (
http://www.quora.com/Typekit/What-are-the-best-Typekit-fonts...) that "all of the fonts tagged with "paragraph" have been hand-hinted to perform well, even in the most unforgiving environment (
cough Win XP
cough)" as said by Mandy Brown, Community Manager at Typekit.
This is very useful because these fonts look really awesome in Windows (which is still the vast majority of users for most sites).