Some of the SSR villas don't have a view of the fireworks at all, some can see them very well and some can even catch a glimpse of Illuminations and even Wishes in the distance.
We had a 4th floor room in the mid section and had a great view of the midnight fireworks. Since all of the PI fireworks are above ground (no ground/water displays like Illuminations), you can see everything very well from anyplace that can see the sky above PI.
For those whose rooms don't offer a view from the balcony, there is also a nice pavilion near the quiet pool (even has rocking chairs). I wouldn't urge anyone to make a special point of trying to see the display however. Unlike Wishes and Illuminations, that both last about 15 minutes, the PI display lasts less than 2 minutes each night (except for possibly July 4 and Jan 1.)
We did watch them every night, since it was so convenient right from our room.
Enjoy!