Took my Exam on Jan 30th, Just received my Score. Got a 256. I did spend quite a lot of time reading these experiences and obsessing over the score correlations. Here’s my CK experience.
Prep time: Nearly 5 months ( took a few weeks break in between)
Sources : Uworld X2 (First pass 77% random,timed), Uworld 3 (all online-76% subject wise)
CMS all forms offline
Nbme 6- 15 mistakes offline (1 month prior)
Nbme 4- 13 mistakes offline (1 month prior)
Nbme 8- 254 (online, 2 weeks prior )
Uwsa 1- 266 (10 days prior)
Uwsa 2- 263 (7 days prior), Free 120q -91%
Nbme 8 was really close to my exam score. Rest over predicted for me. Took nbme 7 nearly 3 months prior to my exam online and was completely destroyed (scored a 207 
). It was mostly filled with twists you will never see elsewhere and was an outlier. Spent most of my time solving questions, discussing explanations with Sp’s and up to date for stuff I felt necessary. I didn’t really follow mtb or first aid , however I would say glancing a bit of mtb for step3 kinda helps.
The real exam, I felt was harder than my assessments and more trickier. Close to uwsa2 but harder. I wasn’t really short of time , had nearly 5 mins on most blocks.
This group really helped me during my prep, thanks guys! Good luck