Can the book 'Grand master Preparation: Calulation' by Aagard be useful for a Class B chess players? I heard in most chess forums this book is for 2400+. Can this book also be useful for Class B players? I'm looking for a book to improve my calculation and planning. If so, in what ways? What would be the best way to self-study this book as a Class B?
I'm rated around 2150 Elo and I used the book two years ago, to solve exercises on the way to work. I could solve approximately 50%, which felt somewhat disheartening, though objectively, I guess, it's pretty ok for my level. I definitely profited from the training.

I wouldn't recommend the book for players significantly weaker than me. Mostly because it's demotivating if you are always struggling to even think in the right direction. I have found that the final instalment of the Yusupov series fits my own level better (i.e. tough but solvable). 

But if you can keep your motivation up, even without much positive feedback, of course you can profit from thinking deeply about just about any position.