Thanks goes out to the Rebuilt Runner for his recent review of Core.
I ran on trails, roads, and grass so I got a good cross-section of how the Core handles on various terrain. They don’t have deep tread so when I pulled them out of the box I was wary about how well they would grip the trails, but in practice they did a great job. The sole feels more like one solid piece than that of the New Balance Minimus (those ones are broken up into separate hexagonal pods) so you don’t get quite the flexibility and surface feel of that model. But the Core feel a little sturdier so they protected my feet better against sharp rocks.
Measurements refer to body size, not garment dimensions. In instances where your body measurements are in between two sizes, go with the smaller size for a tighter fit or the larger size for a looser fit.