"There is some great dispersed camping around the whole area, and the farther from the main areas you go the better it gets."
We went up the trail north of the dunes a ways but didn't find any dispersed camping. Maybe we didn't go far enough. Gave up looking due to the absurd swarms of mosquitoes. This must be the weekend they all hatched, because even the restaurant we ate at in Walden proper was swarming with mosquitoes on this trip.
"The pit toilets are near areas you can get large trucks / trailers / RVs to so the ATV crowd uses them alot, especially on the weekends. They tend to be loud and lit up at night, and in my experience the pit toilets are gross."
We were 50/50 on this one. Two of the pit toilets were normal pit-toilet level -- reasonably clean and usable. The third one we stopped at was notably and memorably bad.
"If you keep going north by the creek or just away from the established sites it gets quieter."
It was quieter on the southern side of the area, but we encountered endless swarms of mosquitoes everywhere, all day long. I probably would have camped on the southern portion away from the ATVs and been fine with noise / crowds that way but for the bugs. Jim noted that yesterday was "not busy at all" compared to the last time he camped there, while I thought the place was fairly overrun with ATVs, quads, and side-by-sides.