PTAD is a good gig if you can get an observed FitRep out of it. Translation: quicker promotion to Captain, and faster buildup of leave time.
Observed FITREPS do not necessarily end up with a faster promotion to Captain. Being pilots you will have nearly 2-3 years of unobserved FITREPS in your files simply due to the nature of training. My first observed FITREP was when I finished flight school and got winged out of Advanced.
It doesn't affect your promotion to Captain by any real streach. Capt. promotions, from what I have been told along the way, and from my buddies who just now starting to pick up Capt. your DOR and lineal number are what matter (in that order). The lineal number you will pick up at TBS. (i.e., read do well, even though you are not competing for an MOS) Of pilots in my MOS with my DOR, I fall out #3 in lineal numbers, so of the group I will be the 3rd 7556 to pick up Capt of those with my DOR.
As of right now, you are lookin at about 5 years to pick up Capt., so don't be too concerned about the FITREP, be more concerned about getting commissioned and getting your wings...