Sinkhole was a nice spot. Decent clean vault toilets. We were there in late April, basically opening weekend, apparently. The campground host, (Sharon, I think?) was extremely cordial and attentive... clearly she really enjoys the job.

Lots of nice hikes close by, as well as sunset opportunities on the rim, which is walkable and also a quick drive. Nice lakes nearby.

The campground is a little close to the main road, but that was the worst thing, and it's not that bad once night falls.