I have been using the Bambino Diapers for about a year now. I really like them. But I tend to be right between the Medium and Large size.
According to the size chart, I should be able to use the Medium diapers (waist 32 - 44 inches). My waist is 41 or 42 inches. But, the medium size does not leave much in the sides to tape into place. So I use the large size (45 - 60 inches) They are a little large, but I can pull them snug and they seem to work great.
I have been using them every night lately and they do keep my bed dry.