I purchased these shoes about a month ago.  I put about 80 miles on them and noticed that something was not quite right.  The Wave Rider shoe has always been a go to for me and I have owned several pairs.  While I like the color, design and weight of the Wave Rider 16 shoes (I had the yellow ones), the heel is narrower in this edition.  When I hit the 80 mile mark I started to notice a lot of discomfort under my ankle.  This was due to the narrow heel digging in on my foot.  I went to a local running specialty store and they confirmed this for me.  Luckily they let me exchange them for a different brand and the ankle pain has disappeared.  If you do have a narrow heel this shoe would be a great option.  The shoe specialist at the store said that the WR16 has the narrowest heel they carry in this style.