I liked 12 Rounds premise and characters overall, but the slow moving pace bothered me. A little too slow for my liking at points. Then ~20 pages from the end things start moving so fast that I had to go backwards on my e-reader to make sure I didn't inadvertently skip a page or something! The ending felt so rushed considering the pace of the rest of the book. As if the author was nearing her page/word limit and had to wrap it up.
Also, the changing POV between Hadlee, Sean, and Connie was a bit distracting...especially the ones in Connie's POV which seemed to come just when I felt like progress was being made between the hero/ine.
The story was definitely compelling enough to keep me interested enough and wanting to know how Hadlee and Sean's story ends. Unfortunately, I found out too late that there was a cliffhanger ending; otherwise, I'd have waited for the sequel to be released before reading this one. I just hate waiting to find out what happens.