I bought one for $5.59.
The meatballs are quite large and enough so that you get some meaty goodness in every bite. They pretty much are enough for every bite from end-to-end. There's a light seasoning to them and they were moist with a soft, spongy feel.
The cheese was placed under the meatballs so that it was thoroughly melted and stretched out nicely when I pulled the two halves apart. There seemed to be more on one half than the other.
Overall, Arby's Italian Meatball Sub was really good with all the requisite components substantially present but also balanced.
Nutritional Info - Arby's Italian Meatball (332g)
Calories - 820 (from Fat - 420)
Fat - 47g (Saturated Fat - 20g)
Sodium - 2260mg
Carbs - 57g (Sugar - 7g)
Protein - 39g