The 210 is well and great, but I went with the 12 twist for my 300 RUM for better results with the 155's through 200's. These bullets are more than capable of handling anything I am going to ask my 300 RUM to do such as taking a coues whitetail or smashing a moose's ribs out to 700 yards.
On the other side of the coin, I have a 11.25 twist barrel waiting to be chambered for my RUM so I can expand my horizons to the 210 grain pills.
Long range shooting is a process that ends with a result. Once you start to focus on the result (how bad your last shot was, how big the group is going to be, what your buck will score, what your match score is, what place you are in...) then you loose the capacity to focus on the process.