If it was me I would opt for the 270 simply because it gives you a slightly broader range of bullets to use and slightly more energy for larger game you might shoot.. you can go up to 150 grain bullets with the 270 where as the 120 is usually it for the 25-06--

personally I like both calibers --I am merely giving my opinion based on your other calibers..but here in the US --many people use the 270 for anything from Pronghorns to deer to bears to elk.. its also an awesome Big Horn sheep gun--

Ripp