Quincy is a great producer, but I'm sorry to say that but the most part of the success was from Michael Jackson, and after from Rod Temperton, Temperton was imo the man behind the success of the production of Quincy Jones, it's Michael Jackson who have given his first big success "Off the wall", after Off the Wall, Quincy was "the hot producer" for Benson, Shaka Khan, James Ingram and Patti Austin (except her, because she has linked to him before that, but he was not the producer of her earlier album), I think that before Michael he have already worked for Brother Johnson but has I think a minor success.
The success for him have begun with Jackson and Temperton, before that he was just a jazz man and not really in the funk world, in fact Temperton have signed his major hit for him, "Give me the Night, "The secret Garden", "Baby come to me", "Ya mo be there", he have signed imo the best song of Quincy Jones, in the Dude he have done 4 music, The dude, Ramazattaz, Something special (this music is magic) and Turn on the action.
He is a great producer, but not really modest, he was in his life a modest composer unlike Michael Jackson and Temperton, in his own album like the Dude, Quincy don't have done his own music, near half of the songs are from Temperton, Quincy Jones could be humble because he don't have done to much in his own album (but in the same his role is the production, nothing less, nothing more).
But maybe it's simply because he begin to become too old, lot of peoples change with the time and he seem really more nervous, before that he seem more modest, I remember to have seen an interview during the 90's for the french TV, when the journalist have said that his stuff with Michael Jackson was way better that what Michael have done himself, he don't have said yes, he just have said that he don't know and if I remember correctly he have said that it was more about the tastes of peoples, and made good comments about Michael.
Peoples could talk about his major role during Michael Jackson career, but if you listen Triumph and Destiny, you can easily find the same elements and the same quality that during his solo career with Jones.