They are BOTH excellent rounds. Look at the numbers for both with 150 gr bullets, they are almost identical. The thing you get with an '06 is more bullet weight choices, as we all know. The "parent" round for the .270 is the .30-03 Springfield, but it is based on the .30-06, however that works. What I can tell you for sure is that years ago I knew one of the most successful guides in Port Heiden on the Alaskan peninsula, and although he advised all his clients to bring something in a .30 caliber magnum, he personally used a .270 and killed everything, and I mean EVERYTHING that walks in Alaska!! So, take your pick. This young man chose the '06, he'll be quite happy.