As someone who hasn't read Kerry Greenwood's novels, I found this entertaining, light- hearted and aesthetically pleasing. Perhaps a little formulaic and not particularly creative in its plot devices, but altogether an enjoyable way to while away an hour on a Friday night. In fact, I may now read the novels after all.
However, as I haven't read them I can't really comment on the criticisms of other reviewers that the storyline was changed and that the main character suffered in her translation from print to screen. Obviously it's often difficult to leave a story unchanged because it just doesn't work in film the way it does in a book; and who knows what other (budgetary) restrictions the production was working within.
The sometimes ponderous camera work and precise, deliberate acting reminded me pleasantly of the Poirot series- although Phryne Fisher is rather racier than the little Belgian. I enjoyed the recreation of late-20s Melbourne, including the bright, interesting wardrobe of the leading lady. I got a little annoyed in some of the middle episodes that the storyline concerning Phryne's sister appeared to be dropped as it was the most intriguing thing about the early episodes, but I was satisfied by the end of the series. I also liked the development of the friendship between Phryne and Jack Robinson, and Hugh & Dot were quite cute too.
Don't sit down to this expecting something mind-altering or deeply intellectual. This is quality b-grade and proud of it; it does its thing very well indeed.