Germans were looking for an high altitude interceptor, and the G55 is the most specialized of the three machines in that work.
According to Sgt. Luigi Gorrini and Lt. Paolo Voltan's evaluations, until 6000 m C205 is pratically unbeatable, while over 10.000 m mustangs and spits outmanuver it. G55 is at the same level of the best allied planes at all altitudes (and is eavily armed).
C 205 is even sturdier than the others two italians, but at the cost of a more complex assembly.
According to Gorrini, either two are preferible to Me 109, that has stiffer controls.
However, a 109 cost 1/3 of the time of a G55 to be built, while te germans build 109s and the italians build G55s, the problem is the organization of the production more than the project.
Finally, the modification of the airframe to solve the problems showed in the Re2005 pre-production series (caused, according to Longhi, by the low quality of "autarchic" alloy), cost only few ours of work, and all the surviving machines at 8 september 1943 were modified, first than germans took them.
DogW