Does a new cd transport require break-in time?

What cable you are using now ?

DH Labs Silver Sonic D 750
0.5 meter

Interestingly, the Cambridge really sounds great with the old Theta DS Pro Prime 
DAC — full-bodied and detailed.  It should sound even better with the  Gungy.
But it sounds too analytical and cold, without depth.
The best sound, analytical but warm, is with the combination of the Oppo and the Gungy, so far.

Synergy between components is very important maybe the CXC and the Gungy are not a good match .The CXC ia a pure transport so its sound is very neutral this allows the DAC to determine the sound signature . I achieved  big improvement with the CXC in 2 main areas :The dynamic spectrum is wider the bass is stronger and deeper and the highs are more precise, Secondly much more details and accurate sound stage.
I realy don't know what eent wrong in your system. 

I believe synergy is the issue as well. It’s really a shame if so.
But, I even if so, I’ll be happy with the alternate combo.
Its a big improvement over what I had.
And I’ll pocket the return of the Cambridge.  Or, alternately, fix the mistracking and keep it as a backup for the Theta (I’m listening to it now — very satisfying.)