I've shot a .30-06 for over 25 years, and love it. I'm big enough to admit though, that there's really no ballistic advantage over the .270 when it comes to whitetail loads. The advantage of buying the old naught-six would be if you choose to hunt larger game, just because you can get heavier bullets for the .30-06 than the .270. The heavier loads would come in handy should you choose to chase bear, elk, or moose.

But all of these critters have been killed by skilled hunters shooting .270's. So I guess it's more preference and comfort than lethality.