Yeah, my dad lived next door or two doors down from him and they were close friends as kids. My pack-rat dad actually kept some of RCD's drawings of knights, cowboys and gangsters, and we still have them (yes, they are signed). He also sent RCD one or two of the drawings and Diebenkorn wrote back with a friendly note. When the SF MOMA did a Diebenkorn retrospective, the multimedia presentation used the drawings.
As for me, I like the Ocean Park series and some of his other work, but have only owned prints not the real deal. Maybe some day. . .