Sites are large and well spaced. Free wifi, several pit toilets along with a new shower/restroom building. No playground or beach. Our kids mainly played at the campsite or rode their bikes around the loop by the sites in the 400s.
In my opinion the sites in the 400s were the most shaded (though none were heavily shaded) and had more grass. Our friends stayed in #402 and their site was similar but with more boulders on the site perimeter. Neither site had good trees for hammocks.
Firewood was a good deal - all you could use for $6/day.
There is a boat launch near the campground as well as a day use area in the park (need to drive there). The day use area is beautiful and you can walk down to the lake, fish, or picnic.
In Ely both the Wolf Center and the Bear Center are great places to visit. If you can only visit one I would recommend the Bear Center as you get to see the animals more up close and the guided tour is very informative.