Finally got my CK score yesterday after those Christmas delays: 253, took the exam on Dec 17
Prep time total: 7 months, but I have two ICU jobs, one full-time and one part-time
For preparation I used KLN - all parts, then Kaplan Q-bank just to roughly assess my performance, overall correct 67%
MTB 2 - whole book, MTB 3 - several chapters.
After that I subscribed UW for 1 month before the exam, finished only 50-60% with overall correct 76%.
Free 150 - 91% correct 3 days before the exam.
Exam itself: here I join common opinion, it's harder than step 1. Almost ran out of time in block 1 and in remaining blocks had 5-10 minutes maximum to spare.
Yes, questions are vague and lengthy. Of all the prep resources UW questions look more or less like real exam, but still real questions don't have exact similarity to anything. I felt uncertain about many questions. BUT don't let this feeling distract you, just keep going! It's doable