We did 7/4 in 2017 and 2018 and 12/31 in 2017 (7/4 and 12/31 have similar setups around the resort). I will caveat this by saying exact setups and crowd behavior aren’t always consistent on major nights like this, so keep a YMMV approach to it and best to keep an eye on conditions at the time.
But for this year, they had the main beach area (the space with the best view) reserved for resort and ADR guests with strict enforcement. There is a separate area within this reserved area for CL guests, but the larger reserved area is for all resort and ADR guests.
They had a DJ on the beach playing music and characters made appearances on/off during the night. It is a lot of fun.
In my opinion, the reserved area never really got crazy crowded to the point you’d need to be stressing for a spot. By 8pm some folks were staking out spots in the sand closest to the side that gives you a direct line of sight to the castle, but you didn’t really need to that early unless you just want to. Places outside of the reserved area will be more crowded than the reserved area itself. Keep in mind the fireworks on 7/4 are also shot from the middle island in the lagoon right in front of Poly - so there’s really not a bad view from anywhere (just subtle differences).
I will say, a BAD storm rolled in this year around 30ish minutes before showtime which sent people running for cover and delayed the show, so I didn’t get to see the full load of folks who would have otherwise come to the reserved area.
FWIW, the resort activities info from this year:
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Hope that helps!