You pose a tough ?. The 30-06 has many bullets available on up to 220 gn, brass is readily available (assume you reload). It was my first high power, and except that it was stolen I would still have it. Now having never owned a 270, but have compared it to a 7mm mag that I have, they are very close on the books in performance. A few years back a reloader would have a small selection of bullets for a 7mm, not so today. If you have the misconception that you are a one rifle owner, then Buy the "06". Otherwise I would recommend the 7mm mag, whether or not you reload the ammo is most everywhere. The 270 has been around a lot longer than a 7mm mag, and a great caliber, but is diminishing in sales,(MY OPINION).
Jim