Programming is the same on both radios, so neither really has an advantage over the other in that respect.
Basically, if you can think of more than a couple of instances when you would like to go scanning on foot, you'll want to get the 396. If you want to use the same scanner between the vehicle and the house/hotel, then again, go with the 396. But if you're going to be scanning almost exclusively in one place (car, house, hotel) without a lot of back and forth, then the 996 is a lot more pleasant to operate.
You haven't mentioned whether or not you need digital capability where you listen, but if you don't, then I'd buy non-digital radios, saving more than half the price of a digital radio, and get both a mobile/base and a handheld.
And I think you may be confused about agencies using AM. The only AM radios out there are CBs, aircraft radios, and shortwave Ham radios. Perhaps you mean they are non-digital?