Yeah, the thing about DIT and FA is that, if you don't know FA really well, then you're spreading yourself thin by having DIT.
Now, it's true DIT will tell you which stuff to concentrate on in FA, but they also add more stuff to learn with their study guide, which means more to learn.
I personally used DIT to just keep me on track so I don't slack...but I also found it hard that after watching the DIT lectures, I didn't have much time left to review the material over again and even hit 50 practice questions...the lectures took up a good portion of the day (but I also paused a lot, and studied along the way) and would write down page numbers of FA where there were tables or lists of stuff to memorize that I would need to go over once more on the weekend.
Bryan