This implies that you do find some reviewers credible, relevant or helpful? If so I'm curious to hear who? Personally (and no offense intended Kal) I don't find any current reviewers "relevant"; quite a few (including Sam) occasionally have useful comments or observations, but I can't imagine using any of their opinions for purchasing decisions. It's really more for entertainment, and Sam often was that IMHO. Something TAS major two reviewers (Hartley and Valin) seem to have a lot of trouble achieving...
not sure this thread is the right place to get deep into an answer to your question.
however; most of the people who are prominent as reviewers (and familiar to me) in the high end are credible to me as consistent to their various biases. which is all anyone can do. it's rare where I will read about an opinion from a particular reviewer and think that their opinion does not make sense considering their history. it's not important whether I agree with their conclusion unless their biases just happen to mirror mine.
I do perceive a bit of politics and pragmatism in reviews of high profile gear regularly. where the prose gets overcooked. but again; I factor that into my take away and usually it all adds up. to me a review is a data point....and little more than that. put enough data points together from various sources that are consistent and you start to get a picture.
likely the most credible, relevant and helpful reviewers to me would start with Fremer for his work with vinyl. beyond that there might be 5-10 people who I also appreciate....but i'm not going down that road. but my personal viewpoint on the whole subject of reviews and reviewers is that i'm at the end point in my gear acquisition process and really have little serious interest in
any review other than my own personal one.
Sam (Ken) has not provided me a useful data point 'ever'. but maybe i'm not his audience....so who cares what I think.
I respect people who take the trouble to write reviews. one time I tried to do it and found it's not that easy to put that much effort into explaining your perspective.