WillyNilly, that reminds me. Not long ago, I had a couple of situations where I gave a "middle-of-the-road" rating. They were books that I truly was torn about! It wasn't a 1....but it wasn't a 5.... I wasn't sure what to put it as!
The hero was excellent. Very well-rounded and the part of plot that involved him was terrific. The heroine was horrible! I don't know what the author was going for, but she totally missed the mark on this woman. I wanted to slap this woman upside the head more than once while reading about her! I, seriously, felt like the author accidentally created a personality trait in the character that she hadn't intended to. And, as a result, she made this woman a farce. Totally distracted from the plot.
And then there was a book that was so, so good until the last chapter. I was reading this book and loving it! And then the author did this quick "wrap it up in 2 pages" ending that left me wondering if I'd missed a chapter or something. Turns out, I wasn't the only reader who had this "drop off a cliff" feeling when they got to that point. It was so completely bizarre! So I rated this book in the middle. It was a 5 until the ending. I averaged out the 5 book with the 0 ending and gave it a rating in-between. And I explained why I did so - as did everyone else!
So, although I tend to be like you and do the 1 or 5 stars more often, there are times when neither one of those works for me!