I recently read "U is for Undertow" by Sue Grafton. This is the latest book in her alphabet series about Southern California private investigator Kinsey Millhone. The series started with "'A' is for Alibi" (1982) and "'B' is for Burglar" (1985) both of which I quite liked. I have read the rest as they came out but have felt for some time that the series has been gradually going downhill, an opinion that this book didn't change.
I am a little unsure of exactly why I haven't liked the later books as much but there are a few things I can point to. In the first book Kinsey is 32 in 1982, in the latest she is 38 in 1988. So the the setting of the books has increasingly diverged from the present. I generally prefer books that are set in the present (meaning the same time as they are written). Of course this is a problem with a long running series character but I think I prefer the alternative choice where the setting stays in the present and the character ages slower than normal people. Another consequence of this being a long running series is that a lot of back story has accumulated and tends to get repeated for new readers which I find tedious. Also the latest book is 403 pages while the first two were 215 and 211. This is a little misleading as the earlier books have more lines per page, still they are substantially shorter. I find established authors (Steven King for example) have a tendency to become excessively prolix, perhaps because they no longer have to listen to their editors. I think shorter is often better.
So in summary, like Iron River , this isn't a terrible book, but if you want to give this series a try I would start at the beginning.