I'm not a four-engine pilot, but I do know that a lot of upgrade work went into the FSX versions of the DC-6. Upgrades to the exterior models as well as the VC. I've read complaints by people who can't get the DC-6 or the Constellation to operate correctly. Evidently the upgraded gauge files demand exact attention be paid to the aircraft operating instructions. The upgraded Convair 580 is similar, I know for a fact that you can get away with some things in it, but if you don't perform the start up correctly you will not be getting away with anything.