I have never needed to break in my Asics, they fit perfectly from day one. I have had many pairs and when I'm fitted at the running store they put me in the same type year after year. They watch me walk and because I roll out a bit on the outsides of my feet I get that type of Asics runner.
I wrecked my knee in a pair of neutral Asics and had to go for physio. It pays to be evaluated, sure beats the pain!
I also buy Thorlo (sp?) socks for running in, keeps my feet cushioned nicely.