Far from a cosmetic makeover, and Ken's job title rather belies his contribution to the sound and design of the products. Simply, if Ken doesn't give it the say-so, it doesn't get the go-ahead.
The man is an old-school audiophile and inveterate tweaker, with experience going back to his days as a radio operator in merchant ships many many years ago - how many is shrouded in mystery, but it's not quite back to the days when you had to wind up a handle before tapping out messages on a morse key.
He's been involved in the design of just about every model in the Marantz range going back into the mists of time, and the Brand Ambassador title only came about a) because they had to put something on his business card and b) he was spending so much time on the road worldwide demonstrating the products and opening up new markets, such as China, for the brand.f
This interview from
The BAJ predates the Brand Ambassador title, but will give you some more of the background if you're interested.
IMHO the difference in sound between the KI products and the standard ones is consistently well worth the money - but take a listen and decide for yourself.