I can never tell if when people use the term "rehash" if it's in a negative light or positive. I tend to see it used in a negative connotation, which baffles me when used in terms of hard mode versions of dungeons. The look-n-feel might be similar, and only to the extent of location/environment but path is different and the name is shared. However, the mechanics between "normal" and "hard mode" dungeons aren't (beside the hack-n-slash/tank-n-spank, but honeslty if you get down to the basics everything is a rehash of everything). I view the hard mode versions as a fresh version of previous content.