The .257 Rob AI is basically a .25 Creedmoor.
250AI
I wish I had gone with the 250AI over the 257Rob as it fits well in a short action.
In all practical sense, the 6.5CM is better than both.
I like the Roberts, Swede and 7x57 in a LA. A 3" action would probably be about perfect for those. The 3.4" LA is better, IMO, than the 2.8" SA.
DF