While I personally think the 260 is a great round, the creedmoor is a far better choice. I have very extensive experience so I’m basing my opinion on that. For example, I’ve loaded 147gr eld to a five round average of 2738 fps with an S.D. of 7.8. The brass availability is great. You can get brass from anywhere. The bullet seating depth is excellent and this round can perform. You can load 142gr hunting rounds, you can do anything you want with this round that one chooses too.
The creedmoor has a lot more availability as well, and is very beginner friendly. It’s a great round to get more people interested in hunting, precision shooting, or three gun heavy metal. The 260 should of taken off years and years ago, but I don’t think it was ever marketed well.
While I have no experience whatsoever with the 6.5 Creedmoor, I have a lot with the .260 and I own three rifles - two factory guns and one custom, all on Model 7 or 700 short actions - chambered for the “6.5mm Remington” and I love every one of them.