Full disclosure: Mark Kermode is a former acquaintance from when I was at university (between 1993 and 1996). I knew him through his wife Linda Ruth Williams (who at the time ran the English department in Southampton). He appeared in a documentary I shot about film censorship, and then I cut him out in the final edit. After that, every time I saw him out and about (we often bumped into one another at screenings at the Harbour Lights cinema), he'd point to me and say: "I can't believe you cut me out of your documentary!" It was quite an amusing running joke between us. These days, he's a lot more famous (at the time, he had more of a cult following during his days with Simon Mayo on Radio 1), and I've not heard from him since about 2008 or so, but I've always valued his views, even if I too sometimes disagree with them.
But then, I think that is true for all critics, even those I particularly value. One gets a nose for their preferences, prejudices, and blind spots. My all-time favourite critic, Barry Norman, was very partial to westerns and Woody Allen films, for instance. I love both too, but I learned to take his reviews for both with a pinch of salt if I suspected he was being overly enthusiastic. On the other hand, Barry Norman could be overly dismissive of horror or action films, so I learned to adjust my expectations on that front too. :)