We tried it out about 5 years ago, but having to start a file, then set it aside during the turnaround, then STILL have the admin staff check the entries...

...it was easier just to have the admin staff sit there and DO the entries, then confirm their work.  CPA still double-checks the numbers again when the file reaches them (and assembly step re-checks the withholding numbers a final time before delivery to client), and the difference in per return fee vs. sum of hourly staff time probably works in our favor (we speed up with more practice as we go through the Season).