I've messed with a lot of 165's, 180's and 200's and they all shoot great in my rifles. It would be hard to pick which one is the most accurate, as I fine tune every one to my rifles. Tough question. However, I'm sure someone here may think they have a good answer...
As for your first analogy with the 270, I have better luck with the 130's... My first pick for best all around bullet is the 150 gr. nosler partition, but I've found the 130 gr. partition to whip it's azz in the accuracy department.. Of course, YMMV...