I'm actually surprised I finished all 15 stories. To be fair to myself, I read them at night to put myself to sleep, and read other books in between.
The pros (and why I didn't just delete the book from my Kindle): it was very easy reading. The writing flowed smoothly, and the characters were fairly understandable. To try to explain: everyday conversational language, believable dialogue, sentences and paragraphs of reasonable length. If the stories hadn't been mysteries, I'd have given it an extra star.
However, these were "mysteries." All but one of the books, despite being from a couple different series, with different characters, were identical:
1) A murder occurs
2) The police and our heroine, who is related to the police detective but not one herself, but is somehow always allowed at crime scenes, "investigate" by glancing around, saying "yep, it's a murder," and then declaring there's no evidence.
3) Around 3 suspects are identified based on motive. Sometimes there are 4 suspects, once or twice there were only 2.
4) The suspects are interviewed, and these interviews are all identical: accusing the suspect based on the motive, asking them for an alibi, declaring that since they can't prove their alibi they're probably guilty. The suspects are uniformly incensed that they're not taken at their word and object to the word "suspect."
5) Our heroine and her police detective companion declare it's a difficult case and are very depressed about it, requiring large quantities of chocolate or pastries. (This is generally the same day or the next day, by the way.)
6) Deputies are assigned to follow each of the suspects 24/7 and sometimes a press conference occurs asking the public to come forward with information. Information usually takes the form of gossip.
7) A piece of gossip or something similar prompts follow-up interviews with the suspects, during which the suspects will accuse each other. The heroine and police detective simply repeat their original accusations and the accusations from the other suspect.
8) One suspects cracks under the pressure, presumably from the inane tedium, and confesses to murder.
9) Our heroine and the police detective congratulate themselves on solving yet another difficult case with more chocolate or pastries. The whole thing takes less than a week.
The one story that didn't follow this format had the heroine from one of the series keep thinking that an acquaintance who died had been murdered, but there was no actual mystery. I'm not sure what the point of that story was.
I grew up on Agatha Christie and Rex Stout. I don't expect every mystery series to live up to that bar, and I'm resigned to the trope of cozy mystery heroines being sugar addicts, but these just aren't mysteries, cozy or otherwise. There's a complete lack of any attempt at detection, and no attention to any clues other than murder weapon, motive, and alibi.