I dug out an article that compares the .260, 6.5x47 and 6.5 creedmoor. The author is a tactical rifle shooter and because his Accuracy International rifle has issues with small primers, he favours the 260 or creedmoor, but his conclusion is basically that there is no ballistic difference between the three.
Looking forward to the rifle shooter article - it seems to land on my doormat about 3 weeks after Ripp gets hold of a copy!
http://demigodllc.com/articles/6.5-shootout-260-6.5x47-6.5-creedmoor/?p=1