Can feudalism be used as an effective form of government?

If you are reading this page then you have successfully accomplished the task previously set before you.  No one but you could have pulled this off.  No hurry up and set the time machine to bring you back.  We won't know if feudalism will work until your back, but regardless the knowledge you have gained will be invaluable.  Great job.  Prepare your notes as the future is counting on them!