John, Start with this thread link below and work through it at your leisure to become completely familiar with the 660. You can just start with the GPS then over time add accessories as you want. Its currently $750 but Im sure there will be black friday deals after Thanksgiving at Aircraftspruce and Sportys. Maybe $50 off with free shipping. The screen is the same size as a iPhone 6,7 plus. Also the touch screen feature is just as good as the iPhone or Android. Further more it is much easier to update software and data bases. Go back and look at the wiring diagram for the 496 then add another in-out serial port and that is the basic wiring for the 660. You can use the same wiring setup that is for the 496 except you have to use the bare wire mount as stated earlier in the thread. Didn't hook up the audio so can't speak to that part. Before the 660 I had a 796 and the audio in that unit caused white noise in the system that couldn't be corrected. I suspect the the 660 audio will work fine.