Both are great, saw this question before, I believe I recall the post saying something like the 7mm will shoot a 140gr at the same speed the .308 will shoot a 150.
Unlimited amounts of factory 308 ammo out there...in every option you could imagine.
In some ways I may say the 7mm-08 is better than the .308, but then again the best horse doesn't always win the race. Also the .308 is here to stay.
Can't go wrong with either I don't believe.
You really could flip a coin and be happy with either choice, so don't stress too much, they're so close...