Most of the Royal Canin formula's (didn't look at the breed specific one's) have corn gluten meal, brewers rice, beet pulp in the top 6 ingredients (and more fillers down the list) - yuck!
Techinal even has wheat, ground corn, rice hulls and brewer's yeast on top of the above-mentioned in certain formulas so its not a food I'd set out to feed!
I've had more experience with technical and royal canin for cats... I used to work for a cat breeder who fed techinal - 1 cat had liver issues at 3 years old but had surgery and was "okay". At 6 he had 17 teeth removed. Another is contantly at risk for intestinal blockages and is medicated. They are all chubby and have flakey or oily fur and only half the coat they should have had as Maine Coons.
My cat is stuck on royal canin siamese because she won't eat anything else (before I knew anything about reading labels). Even though she gets more exercise than any cat I know, she was 1-2lbs overweight last year!