We have stayed at a lot of COE parks, anything from primitive camping, to some of them like staying in a privately owned park, including full hookups. To see how campers rate the COE park you are considering, go to
http://www.campgroundreviews.com/. To find out the amenities, and what size RV they can handle, go to
https://www.recreation.gov/, search for "RV campgrounds". If you don't know the name of the campground, the website can move pretty slowly. I'd suggest searching on campgroundreviews.com first, then go to recreation.gov, to see what amenities are available and what size RV each site will allow. We use recreation.gov to make reservations, since a lot of people know that COE campgrounds are inexpensive, and many have partial or full hookups.