Noté 4 sur 5 étoiles

As I understand - actually it is like sidebar notes, assotiated with web page. Only those, that use this addon and entered the same page probaly can see my comments and I can see their. Is it right?

Cette critique est pour une version précédente du module (0.43). 

Yes, this is correct. But there is more: interesting comments are shown on our website opencomment.org, and we are planning to implement more features, e.g. to correlate comments about the same topics.