"What very popular and hyped book in the blogosphere did you NOT enjoy and how did you feel about posting your review?"
I can't think of a popular book from this year that I didn't like. Last year I was not too happy with Goving Bovine by Libba Bray. I thought it was very well written, but I just didn't care for the story.
As for posting a review, I always post my true opinion. If I feel that a book is well written, but it's just not my cup of tea, I say so. If I think it was not well written I say so and try to point out why, without being cruel. As a librarian, people count on me for an honest opinion. My blogs are finally beginning to grow and I want my followers to feel they can get an honest and thoughtful review.