For sciences, I'd say TBR by a pretty large margin based on their answer explanations. I needed strategies and tricks more than summaries of what to memorize, so TBR was a better fit for me. They also give triple the amount of practice questions. I did look at EK towards the end when I needed more practice, but I used all the techniques I learned from TBR and that helped me go through them fast.
For CARS, it's EK by a large margin, although admittedly I did not use the TBR CARS book at all.