Umm.... If I had a choice between the 2 calibers you mentioned.... I would go with option C (Neither)
For the 270 WSM, im sure its a great caliber and all but I don't see it solving any problems that thier typical older brothers didn't solve.
As for the 264 mag, pshhhh, please, I'd take a 7mm mag ANY day of the week IF I wanted something balistically supperior to the "standard 308 or 30-06". If the 264 is soo great and godly, why is it almost extinct?
Someone mentioned that they think the 264 win mag has more killing power than a 308? Umm..... Yep I agree with you, and I'd like to add that my 22 LR has more killing power than a 458 win mag.
My advice to you is, if you want to add something new to your gun collection, get something you don't have, like a large-medium bore (338 or even a 375). All this 264, 270, 30-06, 308 are in the same family if you ask me, sure one is flatter than the other, and one can handle heavier bullets than the other, but I place all of them in the same family. Evertying from 6.5MM to 7.62 is in the same family. Next family is anything from 8mm to 9.3+.
My ULTIMATE dream is narrow down my gun collection, that way I don't have the "which gun to take" Syndrome.
Varmint: 223
Work horse: 30-06
Same practicality as "work horse" but flatter: 7mm mag
Large North american game: 338 win mag
Eating me? : 416 rigby
As far as now goes, I have all these calibers (except the 416, I placed an order for it last friday), and many many more.