Whether or not you take the PACE exam should be based on several things:  Do you want the extra credential?  How will it affect your marketability?  Will having the RP designation make a difference to you if you are already a practicing paralegal (salary, responsibility, etc)?  Each student has to make that decision for himself/herself.  However, the national trend seems to be toward certification of paralegals in some manner.  Having the RP credential will put you ahead of the curve!