With so many ranking and grading systems and sites and organisations and institutes and whatnot, I'm finding that the only thing I really can trust and allow to influence my buying decisions is my own impression when actually testing the phone. Or opinions of users whose judgement I trust, for example some of the long time posters here in the MacRumors 'Alternatives' section.
Not only because I have no idea who the people behind some of these "authorities" are, but also because how good a phone camera is depends on so many more factors than specs and tests done in clinical situations. One of them being each user's particular way of using their camera. One camera may have fantastic potential in the hands of someone with a bit of photography know-how and experience, but be too slow or technically demanding for a crappy non-photographer like myself to get any worthwhile photos with.