I've hunted with both, and they are both great calibers. Between the two I would personally lean towards the 270 because of its flat shooting.
I currently hunt with a 7mm and love it, best of both worlds (flat shooting, and knock down power). But it kicks like a mule! I'm looking into the 25-06 for my next firearm. My son will be old enough next year and this caliber looks very promising.