Boxwood is of sure better to carve, but cherry does the job to my opinion. I used European cherry, old from a piece of old furniture and I can make very small details. Not with a chisel but with very small cutters on a dentist drill. I carved faces in boxwood and in cherry and indeed the boxwood can handle small faces but a face of a diameter of 1 cm. is doable with cherry.
In this picture you see boxwood and it is indeed possible to go smaller with this. For cherry this is to small but twice the size it is to do and keep the details in the face. And to make decals or ornaments non faces but something like curls, I would say, use cherry.
American cherry I can't say if it is the same but the European version is very dense.
cherry:
btw, the cherry I made a long time ago and was one of my first carvings.