I’m wondering if maybe you are really asking about Writer’s Conferences?
I’ve been to some author events, and it’s always nice to be able to get a signed copy of a book and to talk to the author, but I’ve never been to one in which you got feedback on your own book. The book conventions/Author Events are for the people selling their books and their fans.
I highly recommend writer’s conferences, but I’ve heard (and experienced) that they’re not all equal. I attended DFWCon in Dallas/Ft. Worth three years in a row and loved every minute of it. I connected with other writers who I talk to several times per month (sometimes daily). I learned a lot. I had Rachel Caine edit the first chapter of my story (and she loved it…talk about a confidence boost). I met agents. It was a very positive experience. This summer’s conference has been canceled, but I’m hoping that maybe, just maybe I’ll make it next summer, though it’s very unlikely since I live on another continent now.
I also attended a writer’s conference in Germany. I left a little disappointed. It wasn’t a bad conference, I just felt that I learned nothing knew. Some of the presentations felt more like an author’s event, in that the presenter was really promoting his/her own work. I don’t mind a little bit of that, but what I want to learn is how to improve my own writing so I can get published.
I hope that answers your question.