Yes, PR is does't ,matter. as PR does not help determine keyword relevance. I've seen sites go from anywhere from 0 to 7 in one update and no difference in the number of visitors the site received from natural search.You do not need to exactly know how Google PR works in 2016 to do SEO, and it may be impossible to know this, as Google does not give us enough information.It's very important to point out that what we see as Webmasters in the Toolbar is TOOLBAR PR - this is NOT the same score Google uses internally.