I read some mixed reviews about these shoes (some saying they were too large, others saying they were true to size).  But, I liked how they looked and wanted to give them a try.  A bit of searching online told me that Elder-Beerman sells this shoe, so I went to a store to try them on while on vacation up north.  I usually wear a 8.5M, so I started there and was amazed they they fit perfectly (even after a day of walking around)!  Knowing that the shoes were a much better price on Amazon, I didn't purchase that pair at Elder-Beerman.  Instead, I ordered a pair of 8.5M from Amazon.  To my surprise, the pair Amazon sent were noticeable tight!  Thinking that the sales associate might have handed me a 9M by mistake, I ordered the half size larger from Amazon.  But, the 9M pair from Amazon were so large that they flopped with every step.  Suspicious, I took the two pairs (from Amazon) to a local shoe store & repair shop.  They measure the (marked) 8.5M pair as 8M's and the 9M pair as 9M's.

I'm returning the 8.5M to Amazon and requested a replacement 8.5M pair to see if I'll get lucky and the third pair will fit.  If not, I'll try some heel cushions (the solution other reviews have noted) in the 9M pair.

Based on my experience and reading the previous reviews, I think that Anne Klein has some issues with marking and/or sizing the shoes properly.  The large number of people being a half or full size off in either direction (and no consistency between sizes) makes me think that the shoes aren't being marked properly.  The flopping at the heel might be caused by people trying on a size that seems too small (because it isn't marked properly), and then settling for the half size large (which is marked properly).