I'm a major air carrier jet guy. My total radial engine experience is a little Stearman time and 45 hours in the T-28, courtesy of the USN. By my reckoning, PMDG has done an amazing job putting this model together. Systems, power settings, performance and damage modelling is probably the best out there. The A2A B377 is in the same class.
Both airplanes are a remarkable testament to operating the real world airplanes. Don Douglas designed his airplanes for two pilots. I am very comfortable running the DC-6 without the FE. All the controls are right in front of you. OTOH, I rarely fly the B377 without the FE running everything on the panel because Boeing designed as a 3 man cockpit from the git go.
Both sim models are outstanding, but for pure fun, i would have to give the nod to the Cloudmaster. Thanks PMDG!