I agree that there is no practice exam even close to the usefulness of the AAMC's. They actually contain past MCAT material, and scores statistically correlate with actual MCAT scores (unlike those from pretty much
any test prep company). You
need to take these to get a good feel for the test and to build your confidence. Plus, the analytical tools for zeroing in on your strengths/weaknesses are very good.
But, of course, that's test practice, not study material.
I only worked with two companies' materials. I wanted to focus on studying the
right material instead of everything that everybody thought was useful. (Of course, I had to hope very hard that I picked a test prep company that focused on the "right" stuff.)
I first grabbed the McGraw-Hill tome
while waiting for my EK volumes to arrive (okay, everybody laugh at me now). It was
dreadful. Never, never, never even open this disaster. I'm not even going to try to eBay it, because nobody should use this.
I got both the "Complete" EK study guide set and the 1001 Questions/101 Passages series.
The slender "MCAT Math/VR" volume may have been my favorite book. It's tiny, but after spending years in Physics, Calculus, various Chemistry classes, etc., you may find yourself in my boat... I spent so much time (and calculator effort) calculating exact values with significant digits and the like that I was lousy at the art of estimating quickly to get a result that's close enough to pick a multiple-choice answer. I may be extra-dufusy, but I'd never estimated logrithms or gotten used to using "10" for the acceleration due to gravity or "3" for pi. Really. This little book helped me do almost all of the math from the MCAT in my head. (As I say, others are probably more clueful than I, but if you aren't, you want this book.)
The VR portion of this book also has excellent approaches (that run counter to much of the test-prep common wisdom), and the 101 passages book on VR is indispensible.
EK's advice on the written sample is pretty bleak ("the purpose of WS is to wear you down for BS"), but can be boiled down to: All WS exercises ask you to do exactly the same thing... but with different "prompt" statements.
Memorize the tasks that the test will ask you to do for the test, and you won't have to read the instructions on the exam. Do all of the things that the instructions require of you. Try to make it good writing, but first make sure you do everything they tell you to.
I thought the Bio content review was excellent, and the 101 Passages was
amazing. Great likeness to MCAT, and great, laser-guided focus on the important concepts and factoids. Love it.
EK's Orgo book was sufficient to remind me about concepts I needed from my classes. The 1001 Questions book was useful practice. It didn't resemble the MCAT, but it was very good practice. The illustrations and flash cards for orgo were bogus. As an example, illustrations showed Markovnikov/Anti-Markovnikov reactions using unsubstituted ethylene as a starting material, so halogenation with or without the presence of a peroxide looked exactly the same. (I just typed it, and I still can't believe it.) I was good at orgo, but if you're not hyper-confident, you might want to consider a different source. The lab techniques portion was laughable and simplistic, but I didn't need any more than they provided for MCAT.
The EK Physics content review was good, but the in-text and end-of-chapter questions were sometimes questionable. Good practice in the 1001 questions for Physics, but they weren't MCAT-like. It did give you lots of practice at doing physics questions quickly. For me, it was a big switch going from physics classes, where you spend a lot of time on often-sophisticated problems and get an exact answer... to estimating, rounding, and working quickly to solve simple problems requiring more conceptual understanding than formulas. EK did a reeeely good job at zeroing in on just the formulas that you need to have memorized for MCAT. Other resources I've seen tended to try to make you responsible for every formula you could possibly use in Physics class.
EK Gen Chem content review was good, I thought, and 1001 good if you want to polish up your speed and skills. Did a great job of focusing in on just the formulas and skills that you need for the MCAT.
Overall, I thought that EK was very, very good for focusing on the concepts and facts you need for the MCAT. Unless you know every topic of each subject cold, similarity to MCAT is less important than focused review materials and skills practice.
Then... as others have said, for getting a feel of the test, there's just no substitute for the AAMC practice exams.
The 101 Bio and VR books most resemble MCAT, but after a certain point, I relied just on the AAMC practice exams because of very small differences in perspective that tended to lead me astray. For example, an EK 1001 OChem question asked me if a CH bond is polar. The EK answer is "Of course; their electronegativities differ slightly." But my training (and, as it turns out, the AAMCs practice exams) point to a different answer: "Electronegativity differences aren't different enough to make any difference in reactions or physical properties, so no." On VR, EK questions interpret questions in a slightly more persnickety way than MCAT, which can actually lead you to "overthink" options and make the wrong choice.
Hope this helps!
