I've fired a couple of Rhinos.
First, the difference in perceived recoil and muzzle climb is PHENOMENAL. The damned thing works very, very well from that perspective.
Second, they are ugly as sin.
Third, the grip is small, the trigger is heavy, and the trigger pull is long.
Fourth, the cylinder and cylinder release are very stiff, you have to WANT to get it opened to reload.
I think of this as a beta-version of the gun. the concept is great! Just needs refinement.