Let's say for the sake of argument that you get a perfect table facing the MK at 'Ohana. The fireworks are about to start. The lights go down, the soundtrack from MK comes up, and here's what you can plan on:
Not every child, but the most badly behaved children in the place, will rush over to your table, stand in front of the windows, and completely block your view.
Their attention span is somewhere in the neighborhood of 2.5 minutes, so the siblings will begin to poke, then push, then slap each other. Their parents have their noses in pina coladas, and haven't looked at the children for quite some time. (As you can imagine, they are grateful for the break from them) These are the parents who acknowledged 30 minutes ago that it is way past time to get the kids into bed, but "the fireworks are starting" and they don't want to miss it.
Somehow the message you get is that it is your responsibility to watch these children, especially when they start climbing on the railings near the windows.
You can forget hearing anything but the kids.
I hope that your experience is different, but humans being what they are, I doubt it.
(in case you wondered, my son stayed in his seat and got madder and madder at the antics of the "window children." We did not ask for a window seat, but got one between 2 windows--straight ahead we could see a tiki-lit pathway to the rest of the resort; to our right was the MK)