I studied exclusively from the CFAI materials….did and re-did the EOC Q’s many times and ended up with above 70% in every category. Did the same on Level 1 as well.
Did put in about 400 hrs on each level as well, but if you have enough time I would definately recommend ONLY studing CFA material and not wasting money on 3rd party providers.
If you’re short on time then perhaps the other materials can help, I don’t know.