Gangazi,
I just took my DAT yesterday, and while I cannot testify for DAT Destroyer, I can say that Bootcamp definitely helped prepare me. My PAT score jumped up significantly from my last practice test on Bootcamp because it tests at a much harder level of perceptual ability. On each of the science questions, it provided explanations (and videos for OC) that really fueled where I should focus my studying to cover my weak spots (like plant biology..ugh!).
In terms of content mastery, I have heard really good things about Destroyer from other Pre-Dents that I know. I ended up just getting a used Kaplan study book to brush up, and then I watched videos like Khan Academy and Crash Course to study the hard sciences.
Overall, if you feel like your PAT score is weak, I would recommend Bootcamp just for the PAT Generators. Beyond the generators, I just used the practice tests because they are set up almost identical to the real deal.
Good luck with your studying! Don't forget to relax and take a break!