Dont listen to the guy above me, residencies release information every year showing what they put value on. The residency directors take surveys and then the average values for categories get published in an annual report.
Class Rank is consistently within the top 4 things that they value.
And before you ask me for source, just google NBME data for residencies, this kind of stuff isnt like hearsay or rumor, its all in plain sight, thats why I get amused when I see threads like this where people argue about what is and what isnt important to land residencies.
Sorry if I am too lazy to copy paste the link, been studying all day and about to watch Game of Thrones.