Here is an article that talks about using MyQuest with a class.
http://teacherleaders.typepad.com/the_tempered_radical/2012/11/why-kids-need-goodreads.html
Unfortunately it doesn’t give the reasons to use MyQuest as oppose to Good Reads
1. It is a closed environment restricted to the school so no information needs to be given a third party to register (Good Reads requires an email) and no people outside the school community can contact the students.
2. The books being discussed are available at the school and students can find/hold them directly from Quest and they can also see other similar books in the You May Also Like section.
3. The dialogue can be monitored and abuse can be reported to the librarian.