The .270 Win. is the toughest to beat common round. Even though 7/08 and 308 are good, and can have higher BC bullets, the .270 is as good in the wind because it's in the wind a shorter time. Also, drops less.
My vote to the other portion of the question, "couldn't have been designed better" goes to the 300 WSM. Better than an 06, with ballistics matching 300 H&H in a smaller compact rifle.
