I thought there were only 13" and 15"
If really you mean a recent MacBook Pro your experience risks to be less than optimal. I'm considering buying one in the future because I very much like the Retina screen, but I'm not sure at all it will work with expected display resolution on Slackware or any other Linux distribution for the moment being. Most up to date info I've found so far is on ArchWiki
and this article is only about small size MacBook Pro