What is the effect of a finding of unfitness under section 707 of the California Criminal Code?

At defendant's preliminary hearing, he made a motion to dismiss the proceedings on the grounds that the juvenile court order was improper. The magistrate denied the motion, apparently agreeing with the People that the correctness of the juvenile court's order was not properly before him. The effort to have the section 707 finding of unfitness set aside was renewed in the superior court, defendant's theory being that because of the alleged infirmities in section 707--as enacted and as applied--he was not 'legally committed.' (See generally, Jennings v. Superior Court, 66 Cal.2d 867, 874--875, 59 Cal.Rptr. 440, 428 P.2d 304.)