Stupid question.......depending on what branch of the military you get into for UHUHS, you can only select from residency positions available for that branch?
If that's the case
Army>>Airforce>>Navy
That's about right, for the time being (I believe the military is ,moving to merge the branches training abilities for the different branches, a tri-branch collaborative if you will). It has to deal with the amount of slots made available to the different branches. The army is much larger than the navy and air force, so there are more residency slots... on the whole though, one would be competing against more people in the army for those extra slots... so I don't know if calling one branch more competitive than the other is fair, statistically speaking.
Also, something to remember, and this isn't for any one poster in particular, just a broad statement - residencies in the civilian world aren't a cake walk either. The military uses a similar matching process, except if you don't meet up with your match, you typically do a GMO (a tour of duty as a gen practitioner before your residency... which is why there are some doc's that don't like GMO's - you will most likely be faced with medical scenarios that you are NOT trained properly/fully for). The GMO could be fun, could be boring, could be horrifying, but in the end it gets you more points on your matching application list for when you re-apply to a residency.
My point is, when applying for civilian residencies, one might not always get into his/her residency of choice, just like in milmed.
Also, USUHS and HSPS shouldn't be lumped together. They are different, and for anyone that wants to know more, PM me or go read around the milmed threads. Just make sure that you know what you are getting into before you apply for either - you are an officer first, and a doctor second. That means you answer to your superiors at all times and might have to take command as a superior officer at any point. You will be placed in scenarios that no civilian doc would ever face... This could be great for some, not so hot for others.
That being said, I am waiting for a decision from USUHS, and I would be honored to attend that university.
Good luck all!