the nursery used s26 gold with DS when he was born. we bought him home on bf and top ups and were told that s26 was good. they said he didnt really need the gold version. he was on s26 until he turned 1 then went onto cows milk. we had no issues at all with s26. he put on weight fantastically and was never constipated at all. good luck with what ever you decide to choose