If you are more familiar with more of a toe to heel drop (this one is 4 mm) then you will notice the difference in this shoe.  I was use to a 12mm.  The shoe is not bad, form fits to your foot and could actually be worn bare footed because of the smooth inside.  The bottom has a better base (wider) than the PureFlow 6.  (I found the PureFlow just a tad tippy.) Nice cushioning, not too much...not too little BUT I could still feel the surface I was walking on so not enough cushioning for me.  I wear a 8.5 across the board in athletic shoes.  This was just a tad shorter but I would not go up any increments.  The difference could be adjusted simply by the thickness of your sock.