I received and installed the AVICH-03 today. It does
not allow control of the factory nav unit (i.e.; typing in addresses) while in motion - you have to press the Back button underneath the screen in order to activate the composite input for the AVICH-03, and once you do that you can't see the factory nav (or any other factory screen) until you press the Back button again to exit that input. And, the AVICH-03 does not appear as a selectable input on the Media screen either. Which leads me to my other gripe - the composite (RCA plugs) input. It's beyond me why they didn't build in an HDMI input into one of the two boxes you have to stuff behind your factory radio. Now for the positives: It does work well and as designed, and (after purchasing a separate Apple HDMI converter for $43.00 from Amazon
Amazon.com : Lightning Digital AV Adapter : MP3 Players & Accessories) allows full mirroring of whatever is on your iPhone's (or Android's) screen while moving. This is really all I wanted, as I can control the factory nav via voice pretty well while driving. Plus, I now have the option of casting Google Maps off my iPhone onto the big screen and controlling it via voice input or typing on the iPhone while moving. Slingbox woks well, also; so now I have live TV on the big screen in my Jeep! With the wired version, you can stream video off any app on your iPhone to the factory screen - I've not found one that was blocked, unlike with the Crux wireless system similar to this one.
In summary, there are probably better units out there - but I believe this is one of the cheaper options to accomplish what I want, so I'm satisfied with it.