To be sure, the mags have advantages over the venerable '06. The .300 Win Mag is probably the King of the Elk camp. The new WSM mags and the Remington Short mags (RUSM) have impressive performance. And Weatherby's rep was made on his flat shooting thumpers. But did you ever notice that all of these new cartridges market themselves by comparing thier ballistic performance with the tried and true '06? Seems the 100 year old cartridge is still the standard by whcih all others are judged.
I usually feel fine in the deer woods using the same caliber that Teddy Roosevelt used in Africa (He also used a 405 winchest I believe).
If I had to have one rifle caliber (Perish the thought!!), it would be the 30'06 Sprinfield.