has anyone done the "How to study chess on your own" workbooks?

i started reading the acctual book and then i was thinking to work through the whole 3 workbooks. i'm 2100 fide rapid and 1900 classical, but i haven't played much classical recently. i just wanted to hear other people opinion on these workbooks, but i wanted to hear more about the boost in play and rating they gave you and how much did they take you to finish. thanks