I'd give it some time and hunt with the 270 for a while before deciding. I'm not opposed to magnum rounds for someone who can handle the recoil and shoot them well enough to take advantage of the longer range capabilities. But the 270 has very similar trajectories and you might just find that with better, modern bullets it kills just as well. Once you get used to a smaller, lighter rifle that has less recoil you might not be as interested in going back.
If I owned a 270 and wanted something larger I'd skip right up to the 375 mag. The 300's don't really offer much of an advantage over 270 or 30-06