You sound like a .308 owner trying to justify a purchase decision...
You don't have to do it at the expense of another cartridge... the .30/06 is a greater cartridge period. It has greater case capacity (.308 = 56 gr H2O/.30/06 = 69 gr H2O) and all else being equal will net 150-250 additional fps, more with the heavier for caliber bullets... it really doesn't matter what factory ammo is loaded to, there is no baseline for comparison, therefore it is "apples to oranges" conjecture.
I am a big .308 case fan and have the whole family in various platforms... but I appreciate the "ought six" for what it brings to the table.
When it comes to medium game, they do the same job, a double lung hit animal is just as dead with either and a gut shot means a long tracking job with either. However if I was heading into coastal grizzly country and want to carry a backup rifle, loaded with 220 Partitions, it would be the .30/06 every time.
If you are only shooting deer, flip a coin, for all it matters.