This sword model is a less forgiving test of Carrara's displacement rendering.[click image for a larger version.] It is fewer polys and has abrupt changes of geometry.

The render is pretty good, though loses some definition where the polys are larger. Some statistics: the low poly model is 138 polys. When rendered with displacement it is equivalent to 2.26 million polys.

Carrara settings:
Import model as a vertex object. In the VM set render smoothing to ON. This render used a setting of 6.
Apply displacement in the object's shader, flipping the texture map. Amplitude setting here was 18. For ZBrush disp maps don't enable subdision.

Both this model and Shonner's are available at the link he gives at the start of the thread.