Canobits is better. I used to feed Canobits to my Labrador puppy. The good thing about Canobits is that it won't make your puppy overweight.He'll be in perfect shape. Also, he's stools will be thicker and less smelly. RC is also good but I'd prefer Canobits to RC.
But, remember whether you feed Canobits or RC or any commercially available dog food, they contain harmful chemicals ( preservatives ). They can be very harmful in the long run for your dog.
My advice will be to feed commercial food only during the growing phase of the puppy ( usually in the first 6-9 months ) and after that switch to home cooked food.