I have used Beta Active for 3 of my dogs, including present one who has been on Beta since puppy-hood. She is an Agility trained red tricolour border collie with a penchant for moving at high speed - at four and a half years she is on her prime, learning every day and will probably keep going till at least 16 or 17 years. Never has a health issue, her coat is in top condition and she passes all her health checks. No digestive problems and regular formed stools.
I also like the bite size of Beta, it encourages the dog to chew, not just wolf things down, no crazy, debatably safe additives, no colours, just good solid nutrition. Absolutely happy with the product, would not change.