I disagree. I'm a big fan of Chandler and his monumental creation, Philip Marlowe. Deckard is quite a different character.
Just comparing the two, Deckard's role is to be a witness to Batty's dawning humanity (as well as Rachel's I suppose). I think that's one of the things that gives the movie the feeling of extraordinary redemption at the end. There's no such sense of redemption in Chandler--the Marlowe storylines revolve around the struggle to keep a moral compass in the midst of societal corruption, in line with the common definition of the Noir genre. [0] (I'm thinking particularly of The Long Goodbye but it's common to all the Marlowe stories.)
Just my $0.02. It's definitely fun to think about.
It only works because of the combination of the setting and the story.