I have the Creedmoor and I am happy. I have never shot the 260 or 260AI or the 264. I do know I can hit 8" steel consistently at 600 yards with no problem. I only missed two out of thirty in an almost ten MPH wind. I am sure you can do the same with the others also.
I have taken four dogs and a crow with mine since Christmas. It is very effective at the range and in the field, as long as you are not carrying it too far! I keep hearing about the brass but I have shot 200 rounds out of 2-20 round boxes of hornady. Thats six firings out of each with no pressure signs. I dont know what their issue is.