1) There are like 12 different made-up words for different types of people (mot, cove, doxie, gixie, spintry, rusher, cuddy, mumper, etc). I constantly had to stop and translate or just ignore them, because I couldn't remember exactly what they meant, and I hadn't discovered the glossary in the back. The ones like dog (for cop), puppy (new cop), rat (criminal) and birdie (informant) are great. They're good imagery and easy to understand and lend nice flavor. Even with the other words, I understand the style choice, and sort of admire it, I just didn't enjoy it. Maybe if there were only 2-3 invented words for people...
2) I liked and understood how the dogs (cops) worked, but I was REALLY fuzzy on who the "Rogue" was and what his place was in the hierarchy. Something like a mob boss, I think, who holds the criminals to a sort of criminal code, and keeps things from getting too out of hand...but I was never really sure. With all the explanation of other things, I think a little time could have been spent on this.
3) The journal format. Just a personal preference, but I don't like novels in journal form. Never have. From reading reviews, I'm not alone. It's just so hard to suspend my disbelief. Beka's always talking about how dead tired she is after a long and eventful shift, yet she has time and energy to write pages and pages of diary, and it all sounds like a final draft, not the rough draft my own journal entries always are. But again, this is just personal preference.
4) Length: I think it could have been streamlined a little to cut out some of the repetition.
Things I LIKE:
1) Beka's voice is great. Very skillful writing. With the exception of all the troublesome terms for people, most of the made-up words are completely understandable in context.
2) I like Beka's character and her doggedness. I also really like Tunstall and Goodwin and some of the other characters.
3) Pounce. Best cat ever. Especially in one scene where he brings Kora and Aniki some cute gifts.
4) I like the idea of the pigeons carrying the ghosts of the dead, and how Beka can hear them. I do sort of wonder if someone with so powerful a gift should be risking her life daily on the streets.
5) It's not a romance. Romance is fine, but it's so refreshing to find a book that isn't. Various characters do hop in bed, and there are other references to such behaviors, but the main character is more concerned with fighting crime than finding a man.
6) The awesome world-building around the life of a dog (cop).