If it comes to those two.....Piney Orchard for sure. I was shopping for homes in both of those and just didn't like Seven Oaks at all. I couldn't see myself giving directions to my house by saying "turn at the adult book store and go past all the abandoned buildings and tattoo parlors........."
Seven Oaks is bad news in my opinion.
On another note. I can tell you that we considered Piney Orchard until we found a nicer/bigger townhouse in Quail Run which is in Severn. We instantly fell in love with this neighborhood and it was tens of thousands less that Piney. Worth checking out. There are SFH's here as well.