I think Red Barn is a good choice in the Sioux Falls area as the other 2 campgrounds we saw were both in-town right next to the interstate system. Red Barn is in the country, maybe a half-mile away from I-29. You can still hear the freeway noise in the distance at night, but the campground was very quiet. It looked like the majority of the population at Red Barn are seasonal campers, there for a month or the whole summer. However, the majority were newer, kept up nicely, with flowers and outdoors lights. The owner does seem to have a real interest in old cars (particularlity Mustangs). There are quite a few old cars stored and just sitting around the back part of the grounds by their barn, which does make that part of Red Barn look trashy, but the rest of the main campground was clean and neatly trimmed.
The people that run the place were friendly and have Good Sam Discounts. The majority of the spots are shady and graveled. Our site was a pullthru, but definitely not at all level, tested the limits of our jacks to even-out our RV. Red Barns restrooms and showers may be the cleanest I've ever come across. Each shower had it's own large curtained changing room area with a seat, a shelf and 2 hooks. Large shower stalls with lots of hot water and great shower heads. Restrooms and sinks were equally as spotless. Our utilities worked OK but water pressure did seem to fluctuate with the time of day. WiFi signal was not the strongest but did work. Has a decent sized pool and playground for kids. There is a good sized Sunshine Foods grocery store on the southeast side of Tea for supplies.