Taking Kev's point first, I am always conscious when writing a review that my view may be very different to someone else's. If anything, I tend to find I am erring on the side of caution, saying such things as "some may feel . . .", or "this may concern some people more than others" etc. This can apply both to the musical content of a recording or concert and also to the way the music is played, whether this be in respect of style, technique or other aspects of musicality.
Any reviewer or critic immediately lays themselves open to the question: "Could you do any better?" In most cases, the answer is clearly "No", but one is still entitled to give your own honest opinion - so long as it is clear that that is all it can ever be.
I see no point whatsoever in a review that does nothing more than list the programme items without giving any personal reaction whatsoever - all that does is to give a free advert to whoever has produced the recording. Equally, I have often been prompted to explore a recording even when the reviewer has not been particularly impressed by it, because he or she has given enough background to indicate that it may appeal more to me than it did to him.
I think a review should also be able to supply some additional background to the music or performers, putting things in context, and should also take into account the circumstances regarding the recording or concert - for example, a recording produced by a band and primarily intended for their own audiences and contacts should be treated somewhat differently to a purely commercial venture from one of the "big name" bands.