I stayed at Cherry Hill Park with some friends for vacation. The location is convenient for traveling to the surrounding area. There is a metro bus stop on-site. You can get a metro pass right there (works for the bus as well as the subway). We took the bus to the metro subway station, and from there to the Mall in DC, and to the National Zoo with a transfer. It was also easy to drive to I-495 and down to Six Flags America.
We stayed in the tent camping area, which was a fairly small portion of the entire campground. The tent area was well shaded, with a cold-water tap and wash basin, and a bath house nearby. The bath house toilets and showers were always clean, and the bath house was not overly lit outside but amply lit inside. Never had a problem with sufficient hot water. Each camp site had a dimly lit light stand at the entrance (convenient for navigating your way at night) with a power outlet. We comfortably fit 3 tents in our site. The highway noise can be disturbing at night, but the helicopters and tree frogs were worse for me. Ear plugs come in very handy. There were also a few larger group tent areas scattered around the park grounds. There is construction near the entrance to the park grounds, but that isn't noticeable from the tent area. There is wireless internet throughout the campground, and it was sufficient for our needs.
The camp store (opens 7:00) was fairly well stocked, and there is a supermarket up the road (also a Home Depot and Best Buy). The cafe (opens 8:00) near the pools and theater is convenient for coffee and light breakfast (probably lunch, too). The outdoor theater was showing movies nightly while we were there.
Overall, a very convenient, economical option for staying in the DC area with most of our desired amenities.