Pilothawk, is this on the general/corporate KOA website or are you looking at a specific campground? I ask because I've booked many sites at different KOAs over the years and never seen sites described this way. I'm thinking maybe it's one particular campground using it to describe some of their sites (i.e. "this section of the park will fit most average sized RVs", something like that?). Each campground does use their own descriptions for sites within their park - big rig friendly, for popups and smaller RVs, etc., so perhaps that's just what you're running into. I would not let that determine what type or size of RV you buy. The vast majority of RV parks out there have at least some sites for the largest of RVs. Our current 5th wheel is 35' long and we still go to most of the same places we went with our 27' TT.