A very dense and difficult book, but it works well as a reference guide. It took me a painfully long time to get through. It’s highly compact, with a lot of information, no drawn-out explanations, and no exercises. That being said, it belongs to a different era, and I don’t know how useful it would be as a textbook for learning. I found the explanation of concepts I wasn’t familiar with confusing, though it does have some ingenious rules and mnemonics, and it was helpful in shoring up things I already knew.
A good reference guide, though not great for learning.
not sure i would endorse it but the following explains why it's useful for many
Five Books The best books on Learning Latin recommended by Harry Mount
So the best books on learning Greek for our next interview! Harry, let’s move on to—I don’t know what you call it—but what I certainly know as the Bible. I have here Kennedy’s Shorter Latin Primer though I imagine you recommend the full-length version?
Harry: Yes, there’s the blue one, which I’ve got here and there’s a later one, with a red cover. They’re both fantastic. It is the Bible because it has all the conjugations of the verbs and the declensions of the nouns. It also has, in very concise form, practically all the rules of grammar and syntax. It’s a very dry book. You’re not going to find any jokes in it, but absolutely everything is there. It’s the ultimate rulebook of Latin. It’s actually very short. It’s a very thin volume, because there’s no excess verbiage at all.
It’s so efficient. It’s so economical. It’s my favourite book.
Harry: It’s amazing. Kennedy was, I think, a Latin master in Liverpool. My father told me that because every year whole new generations of school children bought the book, the borders of Lake Geneva were filled with huge villas lived in by people like Kennedy, Hillard and Botting — all these people who wrote Latin grammar books before it had this great decline. They became, very early on, standard books, because they were beautifully worked out to be extremely efficient in the delivery of information. Kennedy is very concise, but it has the answer to every problem in Latin in it.
---
note there is a US edition and a UK edition with some changes in the American edition