Facebook advantage placement+ setup question

This is a tangent question to the bonus videos about the Facebook setup. FB has added so many placements, sizes, types of ads it is very confusing if they work or not. My old school ads only posted to FB feeds and nothing else. Should we allow FB to do all of the placements as we trust they are working? I am hesitant to go down the money pit on placements that will not pan out using winning ads. Any thoughts? Thanks.