One aspect rarely discussed is failure.
Historically failure rates in initial for WSO were around 5-10% (1 per course). I don't know the date for WSOp, and there would be a small loss from OCUs. A fair number of these might be medical.
A WSO failing is still an officer. A WSOp failing is still an AC and if remustered still an AC. The risk for a WSOp going for a commission is low but failure was not unheard of.
Short answer, once you have a commission you are better off.