These took a little getting used to - after having a horrible experience with the new Asics Gel Nimbus that lead to a quad injury, I was pretty cautious about easing into this shoe.  Initially I couldn't get over the odd fit of the heel, which seemed to literally cup my heel from all sides but I've grown to like the extra support.  I have fallen arches in both feet and run with orthotics, which caused me to overpronate badly in the Asic Gel Nimbus.  Thankfully it does not affect my running stride in this shoe. The Mizuno Wave Engima is a true neutral shoe.

The toe box is roomy - I would recommend ordering about a half size up from what you normally wear.  I've always worn an 8.5 running shoe, but had to go with a 9 for these.

Another tip - I've recently tried the Dr. Scholl's Active Series Replacement Insoles and so far have been really happy with them. My foot seems to be staying neutral, the shoe is light, and the inserts are cushy without taking up too much space in the shoe. I'm up to 15 mile runs with absolutely no blisters or sore feet.