For me the two most difficult amenities to find at one campground is 1) secluded drive-up site 2) that is on a lake/river/etc. So because Sleep Creek has many sites with both, we will continue to go back.

We stayed in Piney in June 2019 and it was super quiet and empty, but Labor Day weekend 2020 was busy for the area.  We arrived on Saturday, which is gambling when it's first-come, first-serve, but there were still many sites available.  We stayed at Myers campground, which luckily didn't have any large groups.  There are 2-3 meadow campgrounds that the RVs/pop-ups and the group campers like, so pass those for the smaller spots nearer the water.

Things to note: 

1. Potholed dirt road coming up, a sedan can make it through but will have to take it slow.  

2. Swimming is possible off some of the sites but there are a ton of lily pads in most areas.  Better to kayak and canoe and get it, just beware of underwater stumps.  

3. There is a shooting range on the management area, you may hear them in the distance but it's not near the campground. 

4. One of the most disappointing thing about the Sleepy Creek Management Area is that there does not appear to be any hiking trails.  We instead explored by walking around the campgrounds.  Mushroom hunting was particularly fun in September.

5. Rangers or park management do not come around regularly, so don't expect there to be anyone enforcing the rules.  I say this because we had people partying until 3am the Saturday of Labor Day weekend. 

6. Bring water and firewood.  Sites do not have picnic tables and the fire pits are just pits with no grills.  Sites are marks with a post but many are missing the hooks that you hang lanterns from.