The first time I took the P.E. exam, I self-studied. The second time, I took PPI's course. The third time, I took EET's breadth and depth classes.
I kept all of my materials separate between these three times. When I finally got to the EET stuff, I tried to consolidate everything for that class that I could in the two binders they gave me. This meant that I would put all of my solutions and printed out solutions to the practice problems in the binders also in the binders, even if it made my depth binder barely close. Part of the reason I did this was because I knew it would be more difficult to have to go to a separate binder to find the answer to a problem, and also that it would take a lot longer than having the answer right there would.
I pretty much disregarded all of my prior study materials save the CERM, a few textbooks, and the NCEES practice exams that I had. I bought into EET so hard, and really made sure I knew their resources. It worked for me.