Well, the passages are very good representatives of mcat passages in that they are very experimental. The questions are definitely harder than mcat questions. Also, mcat usually include questions that could be answered by pure "common sense" without reference to the passage. Those are the worst questions for me by the way, and those the type of questions that you don't find in any prep material, including the ICC book.
I haven't done passage 5 yet, but I'm looking forward to it. I did 1-4 so far and passage #9, which was a pedigree. On the first four passages I did good, except for the second passage. However, the pedigree passage destroyed me. I got only 2 correct answers after spending 17 mins decoding the pedigree.
Ochem on the other hand is not that bad. I did the first 4 passages and missed only 2 qs total.
Physics and chemistry are ridiculously hard.
Give the third passage of bio a try. It took me 6 mins to read the passage alone and nearly 15 mins to do the whole thing. But I ended up with 7/7 on it 🙂