I can help you. I applied last year but was denied.
PRGS is very selective. I would say that most of admitted fellows are referral cases. PRGS usually recruit from schools that have private connection with it and take recons from its familiar professors. At least that is how it works here in China. One of my upperclassman got in because PRGS signed an contract with our college to give referred students interview opportunities.
As far as I know, PRGS is more like a consulting firm. Fellows actually work on projects and publish reports, and get paid!
You can look at their websites - fellows name list - profile, try to find anyone who has any kind of connection with you and contact them via email. That actually works.