Folks, I'm on the horns of a delima. I've got an older Pre-Ban AR 15 in CAR configuration. Box stock, just like it came from Colt. Been shot a good bit. Nice fun gun. I am contemplating a swap for a Pre-Ban M1A. Why? I prefer the .308 to the .223 - helps me consolidate my ammo supply. What does the board think? Given similar condition, should I be looking at a even swap? Is the M1A worth more? Am I just nuts?