We tried ADP about five or six years ago.  If you only use Job, cost code, category they would have an import file that you could use to get the data into G/L and J/C.  We also used extras which ADP could not handle.  I will say it was not an easy process, but it was over five years ago, so they may have improved.  I would tie them down on specifics if you plan to go with ADP. Insist on speaking to one of their tech people not just the sales team.

Don