I love this sneaker.  I had a pair of the 623 size 15 D for the last two years that were so comfortable.  I use a custom orthotic and do lots of walking.  Actually waited too long to replace the shoes.  I ordered these in exactly the same size and width as the pair from 2 years ago.  They looked exactly the same but the fit was far off.  They were very narrow.  At first I thought it was for the laces were too tight but after trying to wear them, getting severe foot and toe pain I ended up at the podiatrist.  These shoes are the ones most recommended by podiatrists when using custom orthotics.  You take out the one in the shoe and the base of the shoe perfectly keeps the orthotic sttong and sturdy.

The solution to my problem of fit was very simple but took me a while to figure out.  I just exchanged the shoes for a wider one and went from 15 D to 15 EE.  Now they are even more comfortable than the old pair.  I do believe these ran smaller for some reason but also I am 53 and they say your feet get wider with age.  Also if you do excessive running or walking as I do you need a wider fit.  Amazon is great with returns so you can trial and error till you get the correct size.  And with the correct size, these 623s are very sturdy, comfortable and I highly recommend them.