The meat isn't frozen, and to the extent Five Guys is a downmarket In n Out minus religion, they serve relatively "unadulterated" if otherwise unhealthy burgers/shakes/fries.
Shake Shack is better than either (and, 3x the price of in n out), but is only on the East Coast.
I do agree about Shake Shack though :)
I really want to do the Church/Popeyes/KFC/Grocery/homemade fried chicken double-blind test sometime.