There are definite differences, and all of them are for the better. Suffice to say though, non of the harnesses that come with the AppRadio fit the AppRadio 2.
The AppRadio screams of beta product. The Antenna and microphone connectors come off of a dongle. The single preout comes off of the same connector as the iPhone hookup, the rest of the ports are a mess of connectors, and overall it was just too much unnecessary.
The AppRadio 2 is a breath of fresh air. All major connectors are on the body of the machine, the Microphone port, Steering Wheel Controls, the two preouts, and iPhone connector all have their own separate, sturdy connections on the back frame of the radio. All of the specific wiring for the radio comes out of one singular connector that makes wiring it to your vehicle harness so much easier. Seriously, the AppRadio 2 is a huge improvement install wise.