i had to fix one of these PIETTAs (the single action STARR) recently...the cylinder was not rotating as the crane or star in the back of the cylinder was too soft and the hand was "eating it".
in general, rotating the cylinder is harder than in a colt or remington because of the design of the star or crane, too close to the axis.
the sights are very high on the shooting hand, which is a detriment to serious accuracy at 25 meters, as it increases the shooter´s mistakes on the target (testing a gun at 12 yards and shooting at plates will tell us nothing about serious accuracy) and the grip is not as good as a colt NAVY. The hammer is too slow and has more angle when cocked than other designs. The handling of the gun is also inferior to a COLT, and much inferior to a Remington.
It is too big, and the cylinder is not as positive locked as a colt or remington. I know of another more revolver with troubles, and Pietta seems to have problems with quality control on these guns, as, from the manufacturing point of view, it is quite challenging....and odd design, with complicated machining, and very questionable distribution of parts...like hammer axis, trigger, hand, etc...
too expensive, these Pietta..
i just know the Single action model, by the way, i never handled the Double action Starr.
all the best