I would rather comment on @Dave's points, but since I have no reputation, here goes my comment/answer :-)
I personally was taught not to put "novel" or "to-the-best-of-my-knowledge" or any other weasel words in the papers, so I also do not like the cited examples, if and when I review papers.
What is most often overseen in papers is the "related work" (apart from the discussion section, which I believe belongs more to a journal-type publication), and how the paper makes an advance to the field. The authors should emphasise what the state of the art is, and how the paper advances it. That is what makes me judge for an accept or reject, rather than "incredible results". But it is also true that when you're growing "older" you look for different things in papers, and that "younger" reviewers are more easily captivated by strong claims.