Given a choice of nested sets, I'd use "awesome_nested_set". But "acts_as_commentable_with_threading" seems to say exactly what you want to do; so I'd look into that in a bit more detail.
Given a choice of nested sets, I'd use "awesome_nested_set". But "acts_as_commentable_with_threading" seems to say exactly what you want to do; so I'd look into that in a bit more detail.