Good luck to everyone! I applied for the previous two years in a row, made the interviews, which all went extremely well, but was passed over. I actually am at CDC and probably too familiar with the process. I did not apply again this year because I finally achieved a coveted FTE position and am very happy (that also took a few years to make it through). I have a Ph.D. and many years of experience. It's my opinion that I was a bit too far in my career for the few spots for the "Ph.D." candidates and since I was already here at CDC, it wasn't a good combo. Regardless, the interview experience was wonderful, everyone was great, and I always enjoy meeting the new officers once they start each year. For those with research experience and don't make the cut for the EIS program, I highly recommend the new Laboratory Leadership Fellowship. It is following with the EIS program each year, is 2 years, and will likely lead to a position due to the heightened awareness of lab safety, etc. in Federal Agencies.
Remember that statistically, the odds of getting in are really, really low - just to keep it in perspective
If you make it, that's awesome! Just don't make it your life goal to get in...that could become all-consuming (and disappointing)! There is no formula that is obvious to prior applicants or to those who were part of the interview process on the other side of the table. I had a few interview people who were extremely honest about the process and how it confused them that people they rated super high wouldn't get in...so just be yourself and relax! It's fun and take what you can from the entire experience. I have heard that repeat applicants fare better though, so keep trying (but don't stop your career waiting to make the cut).
My two cents, and (again) good luck to everyone!