I just want to say one thing. This is America, we are all entitled to do as we please (within limitations), so if you want to trade for a 308, go for it.

Whats the actual difference between a 308 and a 270? Nothing. Both will kill deer well past 400 yards if the shooter is capable.

As for which is better, I have never owned a 270, but I do own a 308. Its a bang, flop cartridge on our big whitetails here.