What is the ideal baby formula brand out there for 7months plus baby? Now slowly letting my son to try friso stage 2. Whats the difference between the many brands out there?

I also give my baby boy friso, I personally feel that it was easy to dissolve and it don't cause him any constipation so far. Infact my baby son growth rate for height and weight is 90% thus I never think of changing to others brand since he was fine with it.