I've owned NB shoes for years.  My regular workout shoe is the NB 840V2 in 9D.  Fits perfectly.  So, naturally, when it came time to purchase another basic black knockabout, I ordered the MX623v3 in 9D.  It was more like a size 10.  Huge.  So I returned it for the 8.5...which isn't the least bit tight.  I wish companies would get their QC together!  ...and speaking of QC, the laces were not installed evenly...I had to relace both shoes.  Very Annoying.  However, once I fixed the sizing issue, I really like the shoes!  Great fit and comfort.