We have a 15 year old staffordshire bull terrier that has been fed high quality kibble for his entire life. The last 4 years he has been on a grain free kibble. Before that we had a tibetan mastiff that lived 14 years on kibble - not a bad run for a 135lb animal.
We initially started our new patterdale terrier on a raw diet - as our vet is an advocate. However, doing raw right is not as easy as some people make it out to be. Your sources have to be good, you need to have the proper proportions of different types of meat (RMBs, tissue, organs, etc.) and in the end, I found it no cheaper and much more of a headache than feeding a grain free kibble.
After speaking ot the vet, and feeling that we got an unbiased view from someone who has a specialty in canine nutrition, I think that most people will not see a difference between a high quality kibble and a raw diet. Our staffie bull and our old tibetan mastiff were from lines free from inbreeding, solid stock and were exercised their entire lives.
In the end, diet is just one facet of your dog's health. A genetically sound animal fed a nutritionally balanced diet coupled with proper mental and physical exercise will result in a happy healthy dog that will live a long time.
A raw diet will not address a lack of exercise and will not undo the genetic issues caused by inbreeding or selectively breeding animals for looks at the expense of health.
Before anyone claims any diet as a panacea for an animal with health issues, go to Youtube and watch Pedigree Dogs Exposed.