I bought these shoes on Ebay because they were much cheaper and I didn't want to spend a lot of money on shoes that might not fit right.  I am primarily interested in the negative-heel technology as I'm hoping to improve my posture and decrease my back pain.

Pro's - shoes seem well-made and sturdy.  I've only had them for a few days though, so I'll have to see how they do in the long run.  The negative-heel construction definitely helps with my posture and also keeps my toes from slamming into the front of the shoes.  (I have long toes, and if I order a size larger to fit my toes, the back is too big and rubs up and down on my heel.)

Con's - these run narrow.  The "B" (medium) width feels tight.  My foot runs a little on the narrow side so I'm hoping that over time they will stretch out a little.  For now I'm wearing thin socks with these.

Bottom line - time will tell with these sneakers.