KOA Reservations vs what you get when you arrive

Personally, I avoid reserving through the internet, if possible. Most times, you can call, make a reservation, and get the site number you'll be assigned in the phone call. I do this because I'm quite particular with my sites and prefer to have open space, or even a camp road, out my right side instead of someone else's wall. When you're reserving only a site type through the 'net, like the KOA website, no guarantee on which campsite you'll get.