I mix mine(dry puppy any brand) with raw deer hamburger about 2x week AND don't forget to give them some fish(small portion or youll have big time runs) like cheap Makeral I get for $1 can at Dollar Tree which is GREAT for the adults
My 11 yr old Golden was started on Iams by the breeder, and I kept her on it. We just got another Golden last year and I moved him off of what the breeder was giving him (Diamond) to Iams. It has yet to give my older one any issues and so far it has been great on the new one.
One thing my vet told me.... be wary of grain free dog food regardless of the brand. He said it is linked to heart issues.