I've just finished Prague Nights and thought the same, moderately good. I've read one of the Quirke books and I thought it was just ok, haven't been bothered to get any more.
I think Banville himself doesn't think that much of the crime genre and that shows in the books - it's like he's making some effort but not really trying that hard.
The tv series of the book was on tv here but only in German but I was still able to watch a few episodes. Makes Dublin seem like a gritty, grimy, grubby city, so probably fairly realistic
