I did the destroyer three times. Destroyer is $$$$$$ for the natural science section. dont listen to anyone if they say otherwise. Pat i used crack dat pat (i got really good at hole punching and cube counting because of it). Okay for RC, i probably had the most difficult time with this section because I just sucked at reading before and the only way to get good is practice! i bought crack dat reading (10 test version), and i also bought the datqvault package for $100 which includes all the sections including 7 RC practice tests. So before in total i took 17 practice RC exams (51 passages!!) before i took the actual DAT. the datqvault passages were way longer and dense with information than the actual DAT so if you can score 19's on those you will def score at least a 19 on the DAT. I also read an hour a day of random journal articles on scientific american and discover to boost my reading stamina and speed. With that being said I preferred the map passage method but only wrote key words down (3-4 words max per paragraph). This is how you map a passage in under 5 minutes:
Read first paragraph,
read first and last sentence of each body paragraph,
read the last paragraph (actively reading meaning asking yourself questions about what you just read and what is most likely to be a question).
The DAT is 90% recall questions so mapping is an amazing approach and with enough practice time will not be an issue. I had 10 minutes left in this section because of all the practice. Math I used destroyer as well and its identical to the DAT, actually the QR on the DAT is way easier, I just didn't care about the section because its the least important out of all the sections, but be sure to get an 18 at least just to be safe.