Let's forget about Academy guys for a minute, as that whole process is different...
Historically, enlisted with no break in service (ie, sent to the IRR for a commissioning program) have benefited much more so than a brand new "O-1 with zero." They would get a PCS move from their source (if ROTC) when "regular" Ensigns wouldn't. They also rolled with additional time-in-service for doing the same thing the "regular" Ensign did for the same amount of time. There were a few more small benefits I remember seeing, but I don't recall the details now.
Nowadays, everyone in ROTC that's prior is STA-21 and active, so I'm not sure if the good deals kept flowing. STA-21 started up after I left, so I defer to more recent graduates. That said, I wouldn't be surprised if their Commissioning Orders are different than a brand new, non-prior Ensign.
Um…really swimming out of my lane here...but if there is some sort of "special good deal" for newly-commissioned Ensigns who were "prior enlisted" versus "just hired off the street"…I'd be very disappointed.
I really think the "good deal clock" gets zeroed when you do that swearing-in thingie. Except, of course, for total time served and some other stuff, but I hope it doesn't apply to much else, like "head of the line" at the Commissary or preferred housing treatment.
Historically, enlisted with no break in service (ie, sent to the IRR for a commissioning program) have benefited much more so than a brand new "O-1 with zero." They would get a PCS move from their source (if ROTC) when "regular" Ensigns wouldn't. They also rolled with additional time-in-service for doing the same thing the "regular" Ensign did for the same amount of time. There were a few more small benefits I remember seeing, but I don't recall the details now.
Nowadays, everyone in ROTC that's prior is STA-21 and active, so I'm not sure if the good deals kept flowing. STA-21 started up after I left, so I defer to more recent graduates. That said, I wouldn't be surprised if their Commissioning Orders are different than a brand new, non-prior Ensign.