Honestly I'm not sure that Neville would have made it as far as Harry or if he would have succeeded. Although, who knows. I think Harry's natural way of thinking and his natural skills of being observant and a survivor, in addition to the power that Voldemort gave him by believing in the prophet, allowed him to win. Harry and Neville are so different in personality that I think things would have gone totally different. Plus, whose to say that Neville would have survived the killing curse? Maybe his mother wouldn't have the same kind of magic to protect him as Lily did.