Tested CC today after many years with fcp7. My XDCAM HD footage finally can be played and edited natively without to many artefacts but we are still not there yet. Not to mention how slow the software runs. Scrubling is almost impossible. Hope this will be fixed ASAP.
This footage is not very difficult to play and works just fine in Premiere Pro CC. More likely the problem is your system just can't handle it.
What's your plateform ? I am on Mac
Windows 7. Not sure of the hardware as I was a 'guest editor'.