We were just in Dillon last week at Heaton Bay for one night. Stayed in the electric sites loop C. The water is turned off in the entire park because of a water main break that they are not too anxious to repair. This means that you have to go into town to the marina to get water and the dump station is at the south end of the lake at the Breckinridge Sanitation Dept., and charge is $5. Seems like loops D & E are closest to the water. Campsite is ok and probably great if you have a boat and plan to access the lake.
The area has been devastated by bark beetles and they are clearing entire mountain sides around the lake. We checked out the other two CG's, Lowry & Peak One, but they were not open yet and looked like they were exposed by all of the tree removal.
This was just a overnight stop for us on the way to Aspen to the Maroon Bells which was excellent. If you want a beautiful CO experience, the Silver Bell CG, sites 1 or 5 will accommodate your Bambi.