It depends on how you learn. Personally, I learn very very very poorly by simply reading the material. I mean, I guess if you're gifted with that ability of retaining info you read like that, great. But I totally zone out if I try to do that. I always (almost always) need to rephrase what I read in my own words (i.e. note-taking) before I'm able to learn something.
So yeah. What I end up doing is typing up something for each chapter of EK. Well, that's not totally true. I don't do this for physics or o-chem, because with those subjects, there really isn't a lot to *memorize*.. it's more, problem-solving based on a few principles. So with those, I don't do it. But for bio & chemistry (esp bio), I really find myself needing to take notes... otherwise, I could read a chapter like 3 times and not recall anything 😛... either that, or I'll remember the material for like a day, and by next wk, I won't remember a thing. I really need to make my own notes in order to grasp the concepts for those subjects (and *remember* them!). I'm not sure why that is, but that's just the way it is.
As with all things... YMMV.