Been using this for a few months now, mostly as my SBD feed deck. I am grateful that others interpretted the manual better than myself, because i was wrong, indeed. The line in on the bottom disables the built in mics, so what has been said above is true regarding this deck.
I have had no issues with noise, battery life, etc. Great deck for the price point IMHO, and adds a great deal of flexibility to my gear bag at shows.