We finally know how much time Diddy will spend behind bars after his transportation for prostitution convictions … and a sex worker and exotic dancer involved with the case are weighing in on the conclusion.

As you know … Judge Arun Subramanian ordered Diddy to serve a little over 4 years in a federal prison … but he’s already spent over a year in jail and will get credit for time served.

Sharay Hayes — the exotic male dancer nicknamed “The Punisher” who testified during Diddy’s trial, tells TMZ … at first, he thought Diddy should’ve been freed today for time served — but after hearing the judge’s reasoning for several more years behind bars … Sharay says he concurs.

As for whether he believes Diddy is actually sorry for what he did and is truly a changed man … Sharay tells us — yes, absolutely. He was on top of the world and lost it all … and has no one to blame but himself — that changed him forever, Sharay believes.

Another one of the sex workers named in trial testimony and during sentencing today tells TMZ … he feels Diddy got off too easy, all things considered.

The sex worker — who asked not to be identified — told us he thought Diddy might get 10 years … ’cause of the assault and arson charges. Important to note, prosecutors dropped the arson charges before the case went to the jury.

The sex worker also claims Diddy’s lawyers reached out to him to write a letter for sentencing to defend the mogul … but his attorney advised him not to do that, so he didn’t incriminate myself.