If you go to the IM forum, you will see comments by a program director that CK is viewed as more important than step 1 because it is more clinically oriented. Traditionally step 1 is seen as more important. But given that virtually everyone does very well on that exam these days, CK is becoming a more important discriminator at least for ranking (maybe step 1 is still used more as a screening metric). But as a fourth year in December now, I will tell you that I am very glad I have CK and CS out of the way back in the spring. You don't want to be trying to deal with CK and CS when clinical stuff is out of your head for 6 months and you are trying to interview. Get them done as early as possible. A high step 1 without a CK is kind of a red flag anyway. It looks like you are trying to hide something (your clinical knowledge) and not risk getting a lower score or having to put forth the effort to get a good score that would be required before the interview. It makes you look kind of lazy. Program directors aren't stupid, they know what you are doing if you intentionally push it back so it's not on your ERAS.
I would agree with this. It's not as important if you aced step 1 -- just may not look good but shouldn't prevent you from getting interviews. If your step 1 is below average or even just average (which is what, nearly 230 these days), it is crucial to have at least a passing score on CK and CS when you apply. You won't get interviews anywhere if there is concern that you might match and not graduate on time because you failed CK and/or CS.
