We have used KOA's for 20 years for the times we don't have the camper, the cabin's are cheap and consistent, the bathrooms are normally clean, we don't stay there when we are tenting because they are usually very close to the interstate or main road, we don't use them when we have the camper because we're either mile munching and stay at cracker barrel or Walmart, and when we get to the destination it's a state or federal CG.
They do what they set out to do, give a convenient, consistent, CG, for a comparable price, to camp much cheaper you probably won't have hookups or showers.