You should be reading Cliff's (or some other primary source) regardless. The notes aren't meant to teach you the material, they are meant to compress the facts into an easier to memorize form with the addition of information from various other sources for things that were either left out of Cliff's completely or not explained in enough depth.
If it seems like the notes are too much, that's because they are. The notes are meant to be as comprehensive as possible and the DAT itself will never test on anything more than a fraction of the material, so even if you take every practice test there is out there you are never going to feel like "wow I really did need to memorize every detail of those notes". But I made the notes that way because almost anything from them potentially can show up on the real DAT, so I'd (personally) rather be overprepared than underprepared. But if you feel that you are adequately prepared without them, or that your studying time is more efficiently spent in other ways, it may not be worth keeping up with them. Ultimately it's a judgment call only you can make. Good luck.
