Handloaded, I think the 30-06 handles 180 and 200 grain bullets better than the 308, but even a 180 at 2,630 from a 308 is nothing to sneeze at. Having killed a fair bit of the same game with both, I can't say I've ever seen any difference, and it would likely take several lifetimes to attempt to find any.
I think that about sums it up. I think the main thing the /06 does is provide a bit more on the front end with heavies and extend the range on the longer end. But, If I'm looking to extend my range, the /06 is not my first choice.
