Cruise control. It's a touring bike for pete's sake. Everybody else has it, with the exception of Honda and if you haven't updated your bike for years, you don't count.
Make it feel not so top heavy. I realize this is not easy. My #1 complaint with the big is how top heavy it is.
I don't want bigger bags, they're huge already and there is no free lunch, it makes a big, heavy bike more so. Mirrors are fine for me. ESA, who cares. You can't 'fix' a seat for everyone. Turn signals, meh. Stock tires are gonna be cheap and replaced soon, so no biggie.