The ballistics on the .30-06 and .308 are remarkably similar. Generally speaking, they're close enough in range, bullet drop, and energy that ballistics doesn't have to factor into the decision to any significant degree.3006 or 308 not a lot of difference. But it the 3006 is the better round balistically, the 308 is the more common (imo).
The mags can fail on the m14 or you can lose the clips.
One good thing about the Garand is that it is historical and less then 10 rounds which will be a big plus (imo) when the next administration takes over. I hope they leave a grandfather clause, or i fear i will be forced to become a outlaw, that is if i owned a firearm at all.
As Fred mentioned, if you get the Garand, stock up n the Greek 3006 while you can.
M1 Garands tend to fly under the gun grabbing radar at the moment.I like the Garand just fine and all, but I believe the M-14 has more advantages.