I was hoping to find a replacement for the Nimbus 17 that are getting nearly impossible to find.  I really liked the color scheme on these and hoped against hope they would be suitable.  Not even close.  They lack a lot of the padding and support the 17s had and like other people, I agree the toe box is smaller.  I have small feet to begin with (5.5) and usually have to go up to a 6 in Asics.  However these feel too small at a 6.  So disappointed for these.  The 17s are the only shoe I've found to keep my knees from screaming after 12 hours of on my feet at the hospital.  The 18s aren't even close.