The book is so different it isn't worthwhile to compare. I loved Blade Runner for its visual style, and I've always been a fan of puzzle-stories like that, and I also loved Do Androids Dream of Electric Sheep but aside from "guy who hunts androids has identity crisis," they are pretty much completely different. The whole "is he or isn't he" thing is subordinate to a more character-complete identity crisis, and it gets the opposite answer in the book, about halfway through, I think. I read/watched them more than ten years ago though so my memory is hazy. The main thing I remember loving about Blade Runner as a puzzle-movie was the impact that the paper unicorn had the third time I watched it. Kind of the catharsis of solving a puzzle after a long time combined with the emotional impact of the solution... I was pretty young though, I don't know if it would strike me as either puzzling or particularly emotionally resonant if I watched it today.