We don't use KOAs anymore because we don't need to with the Motorhome. We used them often when we owned our Hybrid TT mainly just to rest for the night. HTTs are not the best for parking lot camping at Walmart or a Truck stop, so KOA to the rescue. They worked well for use because we usually drove until we couldn't drive anymore. No campgrounds would be open, but we knew the KOA would have a clearly defined late arrival policy.
Most KOAs we have stayed at are overpriced. A few were almost reasonable. When we needed them, we were glad they were there. Other than State Parks, I can't remember the last time we paid less than $50 for a night in a Private Campground.
-Michael