Being in the application process myself for about a year and a half now, I think I can chime in with some pennies.
First off, you have to be 30 by the time you begin UPT, that's Undergraduate Pilot training. You're still good but get a move on it, time flies.
As far as the differences between Active duty and ANG/Reserves. Well, the biggest one is that Active Duty is full-time whereas with the National Guard and Reserve it's a part-time affair. That means that if you go the Reserve/Guard route, you have to seek a civilian source of employment. Now, there are what are called ART/AGR positions, which are basically full-time positions within the Guard and Reserve, but as a fresh pilot just coming back from UPT, don't expect to obtain these types of positions.
As far as the training, no difference at all. Everybody goes through the same hole. Now, for the active duty side of the house, you get comissioned (ROTC, OTS, AFA) and when you get to UPT you will compete for a track select and then an assignment. There are several tracks: T-38 (the fighter bomber track), T-1 (everybody else), T-44 (turbo-prop track, leading almost exclusively to C-130 airframes) and the UH-1 track which is helos.
As expected, about 4 or less -38 active duty slots per class, so it's competitive. But then again it all depends, same thing for -44's. Everything else is TONE. Once again, the training is the same for active duty and Guard/Reserves.
If you are Guard/Reserve, the unit you will fly for sponsors you to go to UPT. That means that you will fly the airframe that they fly. In some respects that simplifies things in that if you are set on flying a specific airframe, scouting those particular units guarantees that if you're selected, you will fly that airframe. Only problem is that the Guard is much harder to get into than active, that's the short answer. Lots of connections, good luck and timing as always, statistically more competitive due to the ratio of applicants to slots per unit. I'm adding here but the process can be outright demoralizing, but then again who applies thinking 'oh well I won't get in' right? sh$t... sidetracking
In the Guard you apply to individual units on particular states, each unit has some degree of latitude as far as their application and hiring policies (open to outsiders, only insiders, etc etc).
Reserves work in a similar fashion but the final acceptance decision is made by the HQ in Robins, and they hold two boards per year. In the Reserves your package gets submitted either "sponsored" (meaning a unit has given you their blessing) or "unsponsored" (America still bets for the underdog so why not). If you get approved by HQ as unsponsored you then have to go unit shopping among Reserve units. If you get approved as sponsored then off you go to your unit and into UPT.
Like I said before, it comes down to your particular choices. A lot of Guard guys are also looking for the airline route, so they combine this job with the Guard gig, I'm personally not interested in airline work so my civilian pursuits will probably be in other aviation related careers, like university aviation. My point is that it can be done. Oh, don't expect to land big time gig with the airlines right off UPT. You will still need about a year to a year and a half with Guard flying to be a contender hour wise, but once you get there, you're probably solid. Once again on that one, I'm not interested in that route so my intel regarding hour mins for that pursuit might be off.
So there ya have it. Good luck, don't get discouraged, don't feel bad if you do at times, God knows my days go by SLLOOOOWWWWWLLLY waiting for my ship to come in reading other people's UPT journals. Take care
