First off, I'm a die-hard New Balance customer.  I have very wide feet; EEEE or better.  Go figure. This shoe, along with my Mx622's, run large. I tried a 10.5 in this shoe first (my regular size) and they were too large. The size 10's are snug, but acceptable.  Apparently the difference between these two sizes is more than a "regular" half size.  Because they are slip-on and not lace-up, I figure a little bit snug is much better than a little bit loose.  The fit is that the tongue could be a tiny bit taller, but that's a small complaint.  The sole is not nearly as spongy (shock absorbing) as I would have expected, but this might mean that they wear better.  The sole is quite aggressive, so I'm thinking these will last for quite a while.  I'll update if anything changes in my opinion.