I have been feeding Tino wellness for over 2 years after he realizing he was allergic to his other food, and Lola has only eaten wellness. I have never experienced any problems with them eating it.
Lola has had some tummy rumbles and gas...but we found out from the vet she just had a a bit of an upset tummy (not from the food). The vet told us some pups just have very sensitive digestive tracts and she said it could have been from Lola just eating some grass or something at the park and she recommended we continue wellness because it is a good food made with human -grade ingredients.
My best friend feeds her Shih tzu Purina and that boy has TERRIBLE gas and tummy issues. (Has a way of clearing a room!!!) Whenever I puppy-sit him I send him home with Wellness kibble hoping she will switch!