It would be very rare for an inservice changeover to elect to go to ADFA because fuck that. Generally they'd utilize DASS and study while working or they'd apply for undergrad if they wanted to enter a degree required office career. If they just wanted to go over officer side without a degree they can do the RMC, OTS, RANC DEO course like the other off the streeters.
Enlisted before commissioning.
Pro's:
Cons
I've known great junior enlisted changeovers and great senior sailor / WO changeovers. I've met shithouse changeovers that did it because they couldn't progress in their enlisted career and changeovers that have reverted back to enlisted.
End of the day it's your career and you should do the job you want to do. A career enlisted is no less honourable or respectable than a career on the O side.