Yeah, I'm not great at CARS, but these are definitely difficult; the first section seemed okay, but the second one is much tougher.
Do you find very few of the questions deal with main idea and most of them require going back to the passage to pick out extremely minute details? Reading the passage for main idea and a GENERAL map hasn't been much of a problem for me, but having to go back for confirming small details (especially for Except or Roman numeral questions) is my biggest time-sink...and this hasn't been as much a problem with TPR or EK. Agree/disagree?
Nevertheless, the difficulty of the passages and the (challenging) detail-oriented questions make it good practice, imo.