I am HPSP, matched anesthesiology this year, feel free to ask me any questions. Let me respond to a few things I have seen on this thread though.
If you don’t match you do a GMO tour.
This is half true, and dependent on what year you apply, and what branch you are in. AF and Army if you dont match you do a prelim or TY year, then you can re-apply the next year into your specialty. If you do not match again, then you could do a GMO/flight doc tour to ride out the rest of your commitment, and apply for the residency you wanted through the civilian match (this is fairly common). Some people who don't match are not competitive for their specialty they don't match with in the first place, and will simply choose to go into IM or FM (note, they CANNOT force you into a specialty you dont want to do). I cannot speak for how the navy does things.
Recruiters, like Deans, are paid to lie.
This, while it seems to ring true on the surface, isn't necessarily the truth. Recruiters are paid to fill their numbers, that's what they care about. While some may outright lie (I think this is more rare tbh) most will simply tell half truths. Take anesthesiology for example: the army this year had 12 slots for anesthesia, and they ONLY fill active duty slots, they do not civilian defer. The AF has 6 active duty slots, so a recruiter could in good conscience say "the army has DOUBLE the amount of anesthesiology residencies than the AF!" and technically be telling the truth. However, he would be leaving out a fairly large fact that the AF fills over 50% of its slots via civilian deferment (civdef), and that the AF technically has 22 (this year 32) slots that it can fill for residency. So when a recruiter tells you something, try to dig deeper on the side and find out what the actual facts surrounding a great claim they make is.
As far as civilian deferment I have seen a lot of numbers thrown out that are mostly inaccurate, it really depends on what you want to go into and what branch you are. If you are Army, count on doing a military residency. If you are AF, whether you do a mil or civdef residency depends on what specialty you go into (again, anesthesiology much higher chance of civdef than say FM/IM/peds).
For residency pay, someone said "they only pay you what an officer makes," I'd like to expand on that. Officer pay is very good, especially since you are making the base pay of the officer, along with a basic allowance for substinance (BAS) of about 250/month, and a basic allowance for housing (BAH) which is dependent on where you live (1800/month in San Antonio, for example). All in all, a captain in residency makes about 80-90k/yr depending on years in service and where you live.
Again, if you have any questions let me know.