Are you talking about the Colter Bay Village RV Park? If so, it does allow reservations. We stayed there last summer and had our spot reserved months in advance. We found it to be a lovely campground with lots of nice pine trees and walking paths to Jackson Lake, which is stunning.
There is also a Colter Bay Campground, so you have to make sure to get the right one. It looks to me like the campground doesn't take reservations.
We didn't venture into the other parks, so I can't offer any comparisons, unfortunately.