parsec 3 vs. 2 - what's the deal?

Hello. Should I migrate from parsec-2 to parsec-3? Why? And if yes, then how? The hackage description (of version 3) says "it's well documented ... on the home page", but when I go there, I find docs for version 2 only. If I'm still using parsec-2 for teaching, will this harm my students? J.W.