The 50's and 60's sections are best for viewing fireworks but I will caution that due to the size of the trees (at least this is my experience in the 60's) is that you can see very little from your room or the external walkway outside your room. I found last time that i needed to leave my room and walk out to the path behind the 60's section and near the water to see the fireworks.
The rooms that have been renovated are in the 90's section and I don't believe even believe you can see them from there.