They may not directly answer your specific question. But, there are a number of recent threads about the Creedmoor on this forum. Some members touting the accuracy and some touting the great advertisement by the rounds creator. I suspect precision hand loads and proper range time will result in extreme accuracy from either round. The .308 is the chosen round for many snipers especially prior to the .50 caliber introduction.

My $0.02.....If you hand load, go with either and develop a tack driver. If you don't, go with the .308 and find a factory load your firearm shoots well.