I often wonder how much of his attitude was a face he showed the world. I've heard he was the same person privately and publicly. But his son David's eulogy mentioned that he was like three men: the caricaturish "Ace", Robert B. Parker the author, and Bob the family man.
One way or another, Atkins will fall short of Parker. The only one who wouldn't fall short is Parker himself. Each of us is inimitably different, making it so special to get to know and befriend anyone. When that person is gone, he's gone. But Atkins knows this and doesn't psych himself out trying too hard to imitate Parker.
He's doing what John Gardner did with Ian Fleming's James Bond, bringing Spenser and friends somewhat up to date, picturing how their lives might have continued, because readers want great characters to live on. When I read a Travis McGee book, for example, I imagine what Travis would think of 2013. Part of me wants to believe he's still out there.