So, I have not been able to speak to anybody, but have emailed with their customer support. They gave me a bunch of esoteric differences, and some important ones, but the primary differences for me are.
There are replacing their gear system with direct drive motors. This is important since the gear systems is the primary point of failure on the all the old model Solar Breezes. At least they have been for me. In fact mine is going back now for a warranty repair for that very issue now.
The Ariel can now steer. Before there were wheels that caused it to bounce around as it hit the walls. Now it can maneuver. Those wheels were also a big point of failure as well, as they were gear driven. They would also lose their stickiness over time which causes the NX2 to get stuck more. This is not a problem for free form pools.
Instead of the wheels Ariel can now "see". So coupled with the maneuverability there are sensors to tell the robot where to go. This is important for me as the NX2 gets stuck in corners a lot, and I have a lot of corners in my pool.
Every time they iterate on the model they make some really good improvements, and I expect them to do that again. It is still a little pricey, but I am tempted to pull the trigger anyway.
I really hate debris that floats in the pool, and it skeeves me out every time I swim, so this helps a lot with that.