I applied this year (a bit last minute as I didn’t find out about it until the last few weeks, unfortunately), but have been using CC as a source on what the experience is. There’s a 2017, 2018 thread on YSPA, but not one for 2019. So, I guess this is the “official” discussion for 2019 applicants.
Ah, actually looks like there already is one: http://talk.qa.collegeconfidential.com/summer-programs/2122817-yspa-2019.html.
If someone can tell me how to delete a thread, lmk (whoops).