Super accessible from the Phoenix area, very easy to find. You can choose your own camping spot, and there are many existing stone fire rings and pits that are spaced out decently across the area. The earlier you arrive, the more spots you'll have to choose from; most are filled by sundown. A sedan can easily get across the Flat with some careful maneuvering. Vault toilets are all the way at the entrance of the Flat so plan accordingly. (Or... bring a trowel.)
Lots of families, which means kids, music, and laughter. Never a bad thing, but even if they're not particularly loud, there's no trees or shrubs on the shoreline to dampen the sound and it carries pretty far—especially when kids figure out the lake is basically a giant echo chamber!
The wind can really whip across the lake when it picks up, and it makes it hard to pitch a tent or run a stove. I recommend setting up camp up by the trees if you don't plan on boating/fishing/RV camping to give yourself a bit of shelter from the wind.
No hiking or trails to be had here, but definitely a relaxing, pretty spot.