If you already own a 260 there is very little incentive to trade for a 6.5 Creedmoor. But if buying a new rifle there is no reason to choose 260 over 6.5 Creedmoor. If you don't hand load the 6.5 is absolutely a no brainer. It does everything slightly better with inexpensive, readily available factory loads. Try finding ANY factory loads for 260. I can't think of anything a 25-06 does that a 260 or 6.5 Creedmoor doesn't so better and a 243 just as good.
At the ranges you're talking about there is little difference between 308 and either the 260 or 6.5 other than recoil. The 308 will be in the 15-16 ft lb range vs about 12 ft lbs for either the 260 or 6.5.
