Go on the AAMC site and print out the list of official MCAT topics.
When you are reviewing any chapter in any book, have the list in front of you and literally check things off as you go. For example, when you feel you have a concrete understanding of hybridization orbitals, mark it off. This will help you keep focused on what is absolutely necessary for the MCAT as TBR tends to include much information that isn't necessarily on that list of topics. They do this for a reason though, as those topics are still very much test-able on the MCAT if introduced in the passage itself and going one step deeper into a topic is a pretty good way to determine if you mastered the fundamentals necessary for the MCAT.
I'd stick with the TBR/EK combo. When reviewing, I first went through EK with the topic list in hand. I would then flip through the associated sections in TBR and see what they wrote about. If it was something I had checked off, I would do a very quick read through just to make sure I hit all the major points and understood everything (if you can understand something written two different ways, you're in good shape). If it was a topic I did not feel comfortable checking off based on the info in EK, I would go much more carefully through TBR.
EK has everything the MCAT tests inside it, but I view it more as a skeleton where some extra work is necessary to flesh it out. It's all there but they may spend one sentence explaining something that TBR spends three pages on (and that one sentence may not do it for you). If EK is a skeleton, TBR is an obese man. It has everything and then some and moderation is necessary to work through it.
No experience with TPR but the EK/TBR combo is very effective if used correctly, IMO.
Im the type that likes to thoroughly cover every detail but thats not going to be possible with this book if your aiming for the 3 month schedule. It's crazy because EK is too concise, and TBR is too detailed, where is the happy medium? TPR?
