Our family stayed at Fort Wilkins the past week and we had a great time! We stayed in the East Campground and it was great. Plenty of space, shower rooms, flush toilets, a laundry room, wifi, and a great play ground! The Fort itself is pretty neat... lots of history with a beautiful view of Lake Fanny Hooe. The trail to Lake Superior takes you right down to a pebble beach with a view of the lighthouse. My kids and I love it here! The Fort also has a gift shop available to campers where you can purchase basic needs (and ice cream!) on site.
Copper Harbor is a great place to visit, but keep in mind there is minimal cell service and gas in town is pricey!!
The park itself is beautiful, but the campgrounds are lacking. They are secluded and spread apart which is nice, but they are pretty small and rocky.