Chris is right in his response, in that there really isn't a practical difference. Except in versatility....
Max bullet weight in factory ammo for the .270 is 150 gr., per Federal. Max bullet for the .30-06 is 220 gr., per Federal (
http://www.federalcartridge.com/ammocat20.asp?s1=1)
However, if I were in the market to buy either one, I would consult a good reloading manual (Speer, Hornady or Nosler) first and get some background on each, and a better idea of each caliber's strong points and limitations.
Something to think about is the energy output of each cartridge. In a 165 gr. bullet,, the .30-06 in carries 2800 ft/lbs of energy, while the .270 carries 2355 ft/lbs of energy in a 150 gr. bullet, the largest bullet weight available from factory ammo. That extra ummph might come in handy for a long shot across a canyon at a large elk or mule deer.
If you hand load, or purchase the premium ammo, these days you can reach near magnum velocities and energy levels in the 06'. That might come in handy for that bear or thick-skinned boar. I can easily acheive 1/2' groups with my .30-06, and have no problems at 300 yrds with it.
Recoil is something to be dealt with on any gun. Best advice for either caliber is buy a recoil pad that you can wear at the range, so you don't pick up a flinch. When it comes time to hunt, you will still be used to it, but the one or two shots you take are not going to phase you as you have already become accustomed to the energy output of your firearm. Trust me, they work! If recoil really is an issue, then you might consider a .308 or .30-06 with a BOSS system attached (Browning Firearms). A buddy has one in 7mm Mag. and loves it.
BTW, what maker of firearm are you considering?
Good luck,