I am always thrilled when I get an author comment on a review I have written. My blog is still pretty small so it doesn't happen often but when it does. it's exciting. I generally only review books that I have liked although I don't hesitate to say what I have not liked about a book even though I have enjoyed it overall. So, I hope that an author reading my review feels I have been respectful of their work and a comment from them reinforces that. I guess my basic book geek fan persona feels flattered that an author I have enjoyed appreciated my little post. or review on one of the big bookseller sites.
The first author comment was actually from one of my absolute favorite authors- Margaret Maron. She pasted my review to FB and I was in alt! I was debating about keeping up the blog and it helped me decide to keep going.
My blog will never be one of the big blogs and I'm ok with that. I write it primarily to inform our library patrons about Mystery and Romance books we own or will be purchasing. I have met many of the authors I review at Library Conferences or professional expositions and I have found them almost always to be friendly and open to chatting with their readers. We have had authors come to our library or Skype into our book discussions and they have been very open to all comments. If an author had an issue with what I wrote I would want to know, especially if I had misinterpreted a story line or plot. I think if we respect them, they will respect us.