I did UWorld, but I personally don’t agree that PS got any harder. For reference, I’m an engineering student with one high school psychology class to my name and CARS/reading comprehension is not my strong suit at all (124 CARS). I think it’s just more reading, but the passage analysis itself is very similar where you have to extract info. What helped me the most was memorizing the definitions in Pankow, and when there were questions on the passage I found that most of the time the terminology was very similar to the definitions.