I do not see Mirroring as a goal.  In this I believe I am different from Imago therapists and training.  I see Mirroring as a training tool that does teach lots and lots of critical skills of communication.  If you  love Mirroring, I don't think you need it.  If Mirroring bothers you, I think it is trying to teach you something.

One example of communication trouble comes as many are taught never to interrupt.  I believe that teaching is profoundly wrong.  Sometimes you must interrupt.  I think, in those situations, it is rude to not interrupt.  Mirroring trains you in which is a correct-to-interrupt situation and which is a do-not-interrupt situation.

There are situations where the only rational thing to do is to Mirror.  It is useful to be so well trained that you just automatically Mirror in the right situation.  Generally when someone says something suddenly that may seem profoundly weird, that is an ideal time to Mirror and to let some time  pass before any other reaction. 

Whenever someone tries to stuff their belief down your throat, Mirroring is essential to protect your throat and you self-hood.  In this situation it is a defensive boundary tool. 

Below are links to 6 audiovisual presentations.  Just play each one.  Good luck.