I rarely give 5 stars, I tend to 3 & 4 stars for the most part. For a book to get 5 stars from me means that I feel it was WONDERFUL and it is getting re-read
right this minute.
I also review for a small booksite and I have noticed that I grade harder than a lot of people on my site. In fact, because it's a review site and not my personal review site I've given some thought to quitting - I end up with a lot of crappy books to review.

I make better choices for myself and I don't think it's quite fair for me to continue to review books I would have never chosen for myself.