Perhaps I should have gone to a store for a professional fitting, but my feet feel squeezed.  I purchased my normal size and was aware that they would feel "different" from other sneakers.  I just didn't know what that meant.  I don't experience the "sand" sensation, rather there is a cold, burning sensation.  I quickly adjusted to the heel configuration, and never felt any muscle soreness.
Although I am wearing them now, I wouldn't be if they hadn't been so expensive.
The shoes arrived very quickly.