The problem with this program is the same as the SSP. Delta's #1 problem is staffing Endeavor. They are going to hire the bare minimum from Endeavor to keep up with the contractual obligations, but any extra hiring defeats the purpose of staffing their science project.
Typically if you get called off the street for an interview, the job is yours to lose. The interviewers don't know who your connections are, they just evaluate everyone to the same standard. The reason there is such a high success rate for these guys us that 1) They are extremely motivated (prepared), 2) Delta believes they have earned the interview and puts them on a level playing field. If you happen to get a SSP interview you are not part of that group. I believe you are a totally different category with a totally different standard, because every time Delta hires an Endeavor pilot the problem of staffing Endeavor gets even worse.