For the coast to coast flights there are minor improvements of other domestic flights. In business you get the over the ear head phones on the coast to coast flights, similar to what you get on trans tasman flights.

While for other domestic J flights you get the same flimsy on the ear headphones that Y gets.

I also think the coast to coast flights get a bigger meal, both in Y and J. For instance coast to coast Y get a salad and a desert. Much like on transtasman flights.