I’ve owned both the Mini Worrall and Arri Head 2. The mini worrall served me well for years, but the Arri Head is in a whole different league. The major differences I found from an operators standpoint were:
1. The Arri feels like the exact same amount of force is needed on the wheels to pan or tilt. On the Worrall, the tilt always seemed to require more force. After a bit of time using it I got used to it and could operate well. As you know the tilt on the Worrall is a cable drive, not a direct gear, but it does work well.
2. The overall smoothness of the Arri is way better.
Also if you overweight the Worrall the cable can potentially slip. Not a good thing.
And, as I’m sure you know, the Arri is many $$$ more.
This does not effect my comments above, but I am considering selling my beloved Arri Head 2. I’m just not using it enough in the kind of work I’ve moved into. Let me know if you are interested.