It’s a rule, universally acknowledged, that every discussion of early missiles ends in a disagreement on the capabilities of German wartime developments. But here goes….
The wartime evidence for the state of development of the C2 is good, though the documentation is spread between archives in the US, UK and Germany. It’s quite easy to get hold of facsimiles of drawings, design documents, flight test reports, and discussions on the outstanding problems. These are primary sources from the Peenemunde development team. The post war intelligence interviews with senior and junior engineers from the team are also available online.
The documentation shows the C2 was where it could be expected after a year of flight testing in uniquely challenging conditions. It had not made any intercept trial against a target, had unresolved problems with air burst after engine cut off and the final five test flights were devoted to testing a new fin servo, at least the third type tried in flight testing. Four of the final five flights were deemed to be failures. And it had no proximity fuse or terminal homing seeker. The challenge of integrating it with its guidance system awaited.
Given the development test situation it would be remarkable for it to have been used operationally. And there seems to be no evidence for this at all.
Personally I think the C2 is an impressive technical achievement. The fact that its development was terminated with many problems left to be solved makes it more interesting, not less.
So I think it’s reasonable to judge the C2 as a remarkable prototype, but a significant way from being perfected.