Some are still uncertain when something should be a post or a comment. It is true that in order to locate comments one has to try to remember whether there were comments before or not. I know everyone is trying to put things in the best place. We're all learning what works best for this version of Book Buddies, including me.
Most of the time, it would be best to POST you thoughts. If it's something like Granita's OT (off-topic) post, she (as an occasional Book Buddy) will be able to find your responses best as COMMENTS under her post.
I hope this helps.