Just my two cents....
I don't know why RC is being stressed so much. As part of my SMP, I've taken a full load of medical school courses (which I assume aren't that much different from dental courses) with the med students and to be honest, there really isn't that much reading involved. The only time I find myself reading is to supplement lectures (ie I still don't understand after going over the lecture material).
Actual textbook reading is only "recommended." For subjects like biochemistry, physio, and pharm, I think I may have spent about 2 hours of actual reading....
Thus, I think this whole "reading" thing is a gross exaggeration, but then again everyone is different.
From my experience, at the end of the day, it's what comes out of the instructors MOUTH that is most important and crucial to doing well on the tests.
Finally, RC on the DAT is a freaking joke. The whole thing is just a mad game of search and destroy. If it were like the mcat verbal, there might be some validity to it, but as it stands, there is room for improvement.