Being a part-time coaching teacher and a student myself, I have close connections to students at almost all the time which actually really helped me see the usefulness of this book. Practice makes us better and this book is all about that. There are enough exercises for every common grammar topic which can be found in most of the English proficiency exams or even some major entrance exams.
I really liked the division of sections and how each part gets enough area covered so that nothing important is left out. Plus, the solutions make it easier for the readers to practice and analyse how well they are doing while using this book. Not to forget, the number of questions in this book is massive. From what I've read, this takes a lot of dedication to create such questions and that too in a bulk amount.
Some questions were plainly easy while others were a little complex when compared, I'm not sure why, but I think it was done by keeping readers of all levels in mind. If that's the fact, it's a very smart and considerate practice that others should use. Coming back to the solutions, instead of giving them ahead of each question, there is a separate section dedicated to them so that our subconscious isn't making us skip to answer and miss out on the knowledge we are aiming to get from it.
If there was anything that I would add to this book, that would be a large enough explanation of each concept, which may make the book a lot heavier but will also make it way more useful for the readers. Right now it's more for practice than for understanding and maybe, that was how it's supposed to be still, little theory might just help a lot of people.