Which is the way to go for the best score? Hardcore study 8+ hours a day, 6 days a week for 3 months then work full time, or work part-time and study part-time over 6 months. For arguments sake, assume the hours and money come out even in both scenarios.
It really depends on whether you a) have a good foundation in the knowledge already and just need to solidify, b) are good at cramming and can memorize stuff until the test if you looked at it 3 months prior, c) want to crush your soul or just bleed out slowly.
I did the 3 months route after not having looked at a lot of the prereq type stuff in 5-10+ years. It was brutal, and I was working full time. On test day, there was stuff that I had clearly forgotten but could recognize (does that make it worse?). I did good enough, but probably would have done better if I had given myself more time to actually learn the material better. I used a commercial prep course and finished it slightly ahead of their schedule because I was a little behind on my application timeline. If you’re going to go it on your own, you might want to develop a study program around what the actual testable subjects are, versus just trying to read undergrad textbooks. Finally, there is NO SUBSTITUTE for doing practice questions/tests, they’re invaluable.
That being said, there’s evidence (at least for Step 1), that you basically reach your brain saturation point around 30 days of pure studying. I think that’s with the notion that you probably had a good idea of the general concepts beforehand and were just trying to solidify the information with the mortar between the cracks. Unfortunately, there are a lot of gaps in the brick wall…