I agree with Dozey. The best reviewers, and most interesting reviews, place the film (or music) in context and if that references previous work or perhaps statements by the director etc then fine. That is not the same as pre-judging how good or bad a movie may be but I think it is also honest and acceptable to for a reviewer to say they may have loved or hated previous work and recognise this does create expectations when seeing a new work. We all do that after all.
The best reviews are informative and interesting. I want a lot more than just a star rating.
I think Kermode is excellent. I love the R5 podcast with Simon Mayo. He is honest, he does have strong opinions but does not hide them. He comments on craft and technique not just 'good/bad'. Don't always agree but I think his reviews have intellectual and personal integrity.
Bruce