Ya there folks who say it is just as dead. Which is true, but might be another 100 yards. Then there are those who say, if you shoot in chest or heart doesnt matter. Which is true. But sometimes you don't see enough deer to pass until it in a field broadside.
I do realize with modern expansion, things have come along way. I was on another site, and they just went on and on, how all the kids were using it.
But unless physical reason, or all you own, I don't see why. If you like the AR platform get an AR10 in 308.