When one is applying to be SELRES in a VT squadron, are they better off doing so as an LT and competing on the O-4 board on the reserve side, or waiting a year to see if they're picked up for O-4 and trying then?
"Junior + most qualified" is generally best with most anything in the reserves. "Apply early, apply often" is another saying (it's kinda annoying to hear but it's true).
Other big positives that are specific to a training command SELRES package include quals in the aircraft (vis-à-vis mission quals in fleet aircraft), currency in the aircraft (saves $$ on an IUT syllabus... the next best thing is qualified sometime in the past), experience, ease of commuting (better chance of a part-timer putting in more days per year), and, last but not least, your reputation (it's a big pain to have to fire someone who doesn't get along with others, cancels a lot, etc., so if people with a good rep vouch for you then that's... good). Of course these things are also positives when applying to any job.