I have used NLS for over ten years. I odered it from the States before it was available in Canada. Was always happy with it and still am. Finally this year I decided to try something different - NorthFin. I have used it for three months and like it but don't feel the fish are any better (nor worse) compared to the NLS. Fish colour seems about the same.
I am now feeding a mix of both to my fish and think I will continue to do so. Only difference I see is redder/browner poop with New Life and more grey with NorthFin.