Both are fun, playful skis that are a blast on softer snow and all over the mountain. The Nordica Soul Rider is very easy to ski and has a great rep on this website but it does have a speed limit and is not that great on harder snow. Great at slower speeds and softer snow but they don't like higher speeds. The Armada ARV 96 is still very easy to ski but is stiffer(but still playful in the tip and tails) offering much better hard snow carving performance and more stability. My ARV86 park/bump skis see 60mph daily without drama and the AVR96 is even better at speed. The ARV96 is the "reference standard" right now for a fun, easy to ski all mountain twin that does everything pretty well. Great one ski quiver that is good in all conditions.
Another ski I'd recommend in this group is the Volkl Revolt 95. Similar to the ARV96 with stiffer mid section and softer tip and tail that still does a great job carving on harder snow. A great deal at the price too as it retails for only $400 but like the AVR96 is hard to get as it's very popular. Still prefer the AVR96 over it due to the AVR96 using cap construction tip and tail giving it more shock absorption, lighter swing weight and is less prone to chipping in that area.
ON3P Kartel 98 would be "premium" twin in this class with incredible, beefy construction that is the Kastle/Stockli of the park/free ride community. A more damp, beefier version of the ARV96 at a higher price tag.
All of these you would mount in the "all mountain" binding position which is usually around the -5cm back from center mark or so rather than the center to -3cm mark if you were to use the ski in the park.