We've never stayed in the Elkhart campground but it is the closest. People on the forum have warned the water is not good so you wouldn't be able to test that system if you choose to avoid their water.
We have stayed at several other campgrounds within a half hour of Elkhart and two that are farther away. In order of distance from Phoenix.
- Eby's Pines - we stayed in a cabin here while our slide was repaired but friends stayed near us in their Phoenix. We couldn't find a reasonably priced hotel that allowed pets so we went with a cabin. We had all the bedding and stuff on board so it was just a matter of moving the basics from the rig to the cabin. Very nice campground set back off the road with mature trees and friendly, helpful staff.
- KOA Middlebury - nice but sites are kind of close. They have a few walking trails and a pond with benches. Most of the sites are pretty open so you should get some sun... if there's any to be had.
- Shipshewana Campground North - we did our shakedown here. It was nice, decent size sites with mature evergreens on some. If it is the right season, there is a custard stand on site (huge plus for me). You can hear the highway noise at night... and the clop, clop, clop of Amish horse buggies.
- Twin Mills Campground - much farther east and large campground but well kept with nice sites.
- Potato Creek State Park - a good bit to the southwest. I don't think they have full hook ups and some of the electric posts are shared and are a good distance away from the site. We didn't have our extension cord yet so we had to switch sites to be able to hook up. We really liked the park due to the tree cover and hiking, swimming and boating opportunities. It's kind of far for the first overnight but if you want a few additional nights somewhere nice but not too far to go back, this is a good choice.
We use Allstays
http://www.allstays.com/Campgrounds/Indiana-campground-map.htm You can use your mouse scroll wheel to zoom in to the Elkhart area then click each site to see what they have.
Friends have stayed at Shipshewana South and like it. This puts you very close to the shopping district in Shipshewana (Amish). Distance would place it right at Shipshewana North on the above list.