I had been using the M737s for a year before buying these.  I thought they were the same exact shoe, except for the padding in the heel.  The key difference (huge negative) is the toe box.  These shoes have an extremely short toe box, to the point the tops of my toes are rubbing.  The 737s have a nice tall toebox.  Its a shame, b/c otherwise these are great shoes!

The Version 2 of these look awful, so I will be looking at the Reebok Nano 2.0s.