My favourite part about this thread is watching the old guys debate like Elmer Keith is still around.
Let me sum this up really easily for you, today we have modern hunting bullets that can retain 99% of their weight, shoot flat, accurate, and expand nicely. This makes it so that all the mid-large sized calibers got a massive upgrade over the cast lead, or cup and core bullets of old. What this really means is that all the old arguments are moot, the only ones that should remain are the debates what kind of rifle you like and what kind of distances you're working with.
If you have a 270win and 30/06 and ttsx bullets, they're both going to kill whatever you aim them at. The 270 will outperform the 30/06 after a hundred yards or so, and then lose out after 500 yards. None of this matters because you're going to kill the animal with either round regardless. If you're in an area where you hunt at 500 yards, then it's on you to have something that can make a 10 or less inch group at that range.
Me personally I like the short action, quick cycling guns in non-magnum. Stuff like 308win, 303b (feels like short action), 2 3/4 slugs in an 870, or semi-auto 7.62x39. If I were to get a magnum, I'd most likely get a 270wssm or a 300wsm in a Tikka, but I don't like searching around for $35.00 / box ammo that offers no advantage at the ranges I hunt at (10-75 yards) so why bother?
If you're bent on a 30/06 or 270win shoot both and decide which one you like more. The 270win has an advantage in the 150-400 yard range, kicks a little less, but has less bullet variety. I'd personally go with the 30-06 because I have multiple 308's, I reload so it's flexible in 110-220g, and I never see animals further away than the next corner on a logging road. In BC that means about 75 yards max, so I don't even use a scope lol