My wife and I camped in Patapsco State Park in September 2012.
It is on the edge of Baltimore city in suburbia, so if you are looking for wilderness, this is not the place. Otherwise, it is a perfectly acceptable campground, especially for those who are visiting the Baltimore area. The front gate is well guarded. You need a key pass to enter the campground. Once there, the place feels quite secluded with very minimal road noise. All sites are wooded with mainly mature oak trees so watch out for falling acorns in the fall. We were bombarded by acorns the whole time!
There are only a couple of hiking trails from the campground itself and they are very short, about 1/4 mile. A couple longer trails can be found at the main recreational portion of the park. The one we hiked was ok, but went by noisy roads and under massive power lines.
Restrooms are standard and kept clean. The 2 hosts camped next to and across from the restrooms and it seemed like they monitored them regularly.
For those camping at Patapsco looking for something to do, I recommend visiting old Ellicott City. It is only about 4 miles away and is a very cool old village built on the side of a cliff and over a river. It has several interesting antique shops and quaint restaurants.
All said and done, we enjoyed our stay.