I first Stumbled across John Harvey whilst on holiday last year and having run out of books I found ash and bone, one of his Frank Elder Novels. Having enjoyed this tremendously, I decided to buy the first three books of the Resnick series, many reviewers of Harveys books have mentioned that their is no real need to do this and that although the books go in chronological order, they are still 'stand alone' books. This is largely true, but some of the nuances and subtley in Harveys characterisations can be lost when reading these books out of sequence.
Resnick himself on the face of things could appear to be one of the dullest detectives put to paper, he loves jazz, lives alone, eats sandwiches every meal time and has four cats. Not exactly in your Harry Bosch or John Rebus mould, but then if he was it would detract from the whole point of Harveys writing, and this I feel is that he wishes to create realism and to also offer his readers the credit of being able to add there own assumptions to what at times he leaves unsaid. I personally think this is Harvey's gift, he writes in a prose that is often complicated and gritty, but this creates a feeling that you are reading a book about life itself and not something that has been fabricated beyond all sense of reality (i.e James Patterson).
Lonely Hearts is by no means the stand out book in the series and does come some way short of others like off minor, cutting edge and rough treatment. But if you dont treat this book as a 'stand alone' and look at it as the first in a truly remarkable series of crime writing fiction, then it's simply a 'must read'.