I agree with ipsc that a 7mm08 would be an excellent choice in a such light weight gun, but I have a Sauer 202LW in 270 on the way that will weigh about the same as the Tikka. So I really can't cast any stones.

To answer you original question, I am a huge fan of the WSM's, but I am a bigger fan of the plain old 270. I already have a couple of 270's and am adding another as I have already mentioned.